Dielectric ceramic composition and ceramic capacitor

Abstract

A dielectric ceramic composition includes 100 mol % of an oxide of Ba, Ti and Zr, 0.25 to 1.5 mol % of an oxide of Re, Re representing one or more elements selected from the group consisting of Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Y, 0.1 to 0.4 mol % of an oxide of Mg, 0.03 to 0.6 mol % of oxides of one or more elements selected from the group consisting of Mn, V and Cr and 0.02 to 0.3 mol % of oxides of one or two elements of Mo and W. The ceramic composition further includes a glass component having SiO2 and x in the oxide of Ba(Ti1−xZrx)O3 ranges from about 0.05 to about 0.26.

Description

FIELD OF THE INVENTION

[0001] The present invention relates to a ceramic capacitor and ceramic compositions therefor; and, more particularly, to reduction resistive dielectric ceramic compositions suitable for use as a dielectric layer of a ceramic capacitor having internal electrodes made of a base metal such as Ni and a ceramic capacitor fabricated by employing such ceramic compositions as a dielectric layer thereof.

BACKGROUND OF THE INVENTION

[0002] Recently, a base metal, e.g., Ni, is widely used in forming internal electrodes of multilayer ceramic capacitors for the purpose of reducing manufacturing costs. In case the internal electrodes are composed of the base metal, it is required that chip-shaped laminated bodies including therein the internal electrodes be sintered in a reductive atmosphere in order to prevent an oxidization of the internal electrodes. Accordingly, a variety of reduction resistive dielectric ceramic compositions have been developed.

[0003] Recent trend towards ever more miniaturized and dense electric circuits intensifies a demand for a further scaled down multilayer ceramic capacitor with higher capacitance. Keeping up with such demand, there has been made an effort to fabricate thinner dielectric layers and to stack a greater number of the thus produced dielectric layers.

[0004] However, when the dielectric layers are thinned out, a voltage applied to a unit thickness intrinsically increases. Accordingly, the operating life of the dielectric layers is shortened and thus a reliability of the multilayer ceramic capacitor is also deteriorated.

SUMMARY OF THE INVENTION

[0005] It is, therefore, an object of the present invention to provide highly reliable dielectric ceramic compositions and ceramic capacitors prepared by employing such dielectric ceramic compositions in forming dielectric layers thereof, wherein the dielectric ceramic compositions exhibit such electrical characteristics as a dielectric constant equal to or greater than 10,000, a capacitance variation of −80% to +30% (based on a capacitance obtained at a temperature of +20° C.) in the temperature range from −25° C. to +85° C., a dielectric loss “tanδ” of 10.0% or less and an accelerated life of 200,000 seconds or greater.

[0006] In accordance with a preferred embodiment of the present invention, there is provided a dielectric ceramic composition comprising: 100 mol % of an oxide of Ba, Ti and Zr, the content of the oxide of the Ba, Ti and Zr being calculated by assuming that the oxide thereof is Ba(Ti1−xZrx)O3; 0.25 to 1.5 mol % of an oxide of Re, Re representing one or more elements selected from the group consisting of Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Y, the content of the oxide of the Re being calculated by assuming that the oxide thereof is Re2O3; 0.1 to 0.4 mol % of an oxide of Mg, the content of the oxide of the Mg being calculated by assuming that the oxide thereof is MgO; 0.03 to 0.6 mol % of oxides of one or more elements selected from the group consisting of Mn, V and Cr, the contents of the oxides of the Mn, V and Cr being calculated by assuming that the oxides thereof are Mn2O3, V2O5 and Cr2O3, respectively; 0.02 to 0.3 mol % of oxides of one or two elements of Mo and W, the contents of the oxides of Mo and W being calculated by assuming that the oxides thereof Mo3O3, WO3, respectively; and a glass component including SiO2, wherein x in the oxide of Ba(Ti1−xZrx)O3 ranges from about 0.05 to about 0.26.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The above and other objects and features of the present invention will become apparent from the following description of a preferred embodiment given in conjunction with the accompanying drawings in which:

[0008] FIG. 1 represents a schematic cross sectional view illustrating a multilayer ceramic capacitor;

[0009] FIG. 2 is a triangular composition diagram for showing compositions of B2O3—SiO2—MO in a unit of mol %; and

[0010] FIG. 3 sets forth a triangular composition diagram for illustrating compositions of Li2O—SiO2—MO in a unit of mol %.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Compound powders of BaCO3, TiO2, ZrO2, Re2O3, MgO, Mn2O3 V2O5, Cr2O3, Mo3, WO3 and a glass component including SiO2 were weighed in amounts as specified in the accompanying Tables 1-1 to 1-6 and mixed for about 20 hours by a wet method in a ball mill containing therein PSZ (partially sterilized zirconia) balls and water to thereby obtain a ceramic slurry. The produced ceramic slurry (containing 30% of water) was dehydrated and then dried by being heated at about 200° C. for 5 hours. It should be noted that “Re” is selected, e.g., from the group consisting of Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Y.

[0012] Thereafter, the dried ceramic slurry was ground and then calcined in air at about 800° C. for 3 hours. The calcined slurry was then crushed by employing a wet method in a ball mill added with ethanol for about 10 hours. Next, the crushed ceramic slurry was dried by being heated at about 200° C. for 5 hours, thereby obtaining the powder of the calcined ceramic slurry.

[0013] In a following step, a dielectric ceramic slurry was obtained by mixing and grinding 1000 g (100 parts by weight) of the powder of the calcined ceramic slurry, 15 wt % of an organic binder and 50 wt % of water in a ball mill, wherein the organic binder includes acrylic ester polymer, glycerin, and a solution of condensed phosphate.

[0014] Next, the dielectric slurry was subjected to a vacuum air separator to remove air bubbles therefrom and formed into a thin film coated on a polyester film by using a reverse roll coater. Thus produced ceramic thin film on the polyester film was heated and dried at about 100° C. and then diced to thereby obtain square ceramic green sheets having a thickness of about 5 μm and a size of about 10 cm×10 cm.

[0015] Meanwhile, 0.9 g of ethyl cellulose dissolved in 9.1 g of butyl carbitol and 10 g of Nickel powder having an average diameter of about 0.5 μm were loaded and stirred in a stirrer for 10 hours to form a conductive paste for use in forming internal electrodes of ceramic capacitors. Thereafter, the conductive paste was printed on the prepared ceramic green sheets to form conductive patterns thereon and then the printed conductive paste was dried.

[0016] Subsequently, ten ceramic green sheets having the conductive patterns thereon were stacked against each other with the conductive patterns facing upward, thereby forming a laminated body. Every two neighboring sheets were disposed in such a manner that the conductive patterns provided thereon were shifted by one half of a pattern size along the length direction. The laminated body also included one or more ceramic dummy sheets stacked against each of the uppermost and the lowermost ceramic green sheets having conductive patterns thereon, the ceramic dummy sheets representing ceramic green sheets without having conductive patterns thereon.

[0017] Next, the laminated body was pressed with a load of about 40 tons at about 50° C. along the stacking direction of the ceramic sheets in the laminated body. Afterwards, the pressed laminated body was diced into a multiplicity of chip shaped ceramic bodies having a size of about 3.2 mm×1.6 mm.

[0018] Thereafter, Ni external electrodes were formed at two opposite sides of each chip shaped ceramic body by, e.g., a dipping method, the internal electrodes being alternately exposed to the two opposite sides of each chip shaped ceramic body. Then, the chip shaped ceramic bodies were loaded into a furnace capable of controlling an atmosphere therein and the organic binder contained in the loaded ceramic bodies was removed by heating the furnace in an N2 atmosphere. Then, the binder-removed chip shaped ceramic bodies were sintered at about 1200° C. in a non-oxidative atmosphere with oxygen partial pressure being in 10−5 to 10−8 atm order range. Thereafter, the sintered chip-shaped ceramic bodies were re-oxidized in a neutral atmosphere to thereby obtain multilayer ceramic capacitors as shown in FIG. 1, wherein reference numerals 10, 12 and 14 in the FIG. 1 represent dielectric layers, internal electrodes and external electrodes, respectively.

[0019] Tables 2-1 to 2-6 exhibit a measurement result of electrical characteristics obtained from the thus produced multilayer ceramic capacitors, wherein a thickness of each dielectric layer incorporated in the capacitors was about 3 μm.

[0020] The electrical characteristics of the multilayer ceramic capacitors were obtained as follows.

[0021] (A) Relative permittivity or dielectric constant εs was computed based on a facing area of a pair of neighboring internal electrodes, a thickness of a dielectric layer positioned between the pair of neighboring internal electrodes, and the capacitance of a multilayer ceramic capacitor obtained under the condition of applying at 20° C. a voltage of 1.0 V (root mean square value) with a frequency of 1 kHz.

[0022] (B) Dielectric loss tanδ (%) was obtained under the same condition as established for measuring the permittivity cited above.

[0023] (C) Resistivity (Ω cm) was acquired by measuring a resistance between a pair of external electrodes after DC 25 V was applied for 60 seconds at 20° C. The number following “E” in the notation of a resistivity value presented in the accompanying Tables 2-1 to 2-6 represents an order. For instance, 4.8E+12 represents 4.8×1012.

[0024] (D) Accelerated life (second) was obtained by measuring time period until an insulation resistivity (ρ) becomes 1×1010 Ω cm in a DC electric field of 20 V/μm at 150° C.

[0025] (E) Capacitance variation ΔC/C20 (%) was obtained by measuring capacitances at −25° C. and +85° C. in a thermostatic (or constant temperature) oven under the condition of applying a voltage of 1 V (rms value) with a frequency of 1 kHz, wherein C20 represents a capacitance at 20° C. and Δ C represents the difference between C20 and a capacitance measured at −25° C. or +85° C.

[0026] As clearly seen from Tables 1-1 to 1-6 and Tables 2-1 to 2-6, multilayer ceramic capacitors with highly improved reliability having permittivity (ε) equal to or greater than 10,000, capacitance variation ΔC/C20 within the range from −80% to +30% at temperatures ranging from −25° C. to +85° C., tan δ of 10.0% or less and accelerated life of 200,000 seconds or greater could be obtained from the above samples sintered in a non-oxidative atmosphere even at a temperature of 1200° C. or lower in accordance with the present invention.

[0027] However, samples 1 to 3, 25 to 27, 29, 34, 36, 41, 42, 58, 61, 62, 66, 67, 71, 72, 75, 79, 82, 84 to 86, 108 to 111, 115, 116, 122, 123, 131, 137, 138, 142, 143, 146, 150, 153, 155, 159 (marked with “” at the column of sample numbers in Tables) could not satisfy the above-specified electrical characteristics and further, when these samples are employed, a highly densified ceramic body may not be obtained by the sintering at 1200° C. Therefore, it appears that such samples fall outside a preferable compositional range of the present invention.

[0028] The reasons why the preferable compositional range for the dielectric ceramics in accordance with the present invention should be limited to certain values will now be described.

[0029] First, when the content of an oxide of a rare-earth element represented by Re is 0 mol % in terms of Re2O3 (i.e., assuming the oxide of Re is in the form of Re2O3) as in the sample 36, the tanδ thereof goes over 10.0% or capacitance variation ΔC/C20 deviates from the range from −80% to +30% at temperatures ranging from −25° C. to +85° C.; whereas when the oxide of Re is set to be 0.25 mol % in terms of Re2O3 as in sample 37, the desired electrical characteristics can be successfully obtained.

[0030] Further, when the content of the oxide of the rare-earth element Re is 2.0 mol % in terms of Re2O3 as in the sample 41, a highly densified ceramic body may not be obtained by the sintering at 1200° C. However, when the content of the oxide of Re is set to be 1.5 mol % in terms of Re2O3 as in sample 40, the desired electrical characteristics can be successfully obtained.

[0031] Accordingly, the preferable range of the content of oxide of the rare-earth element Re is from 0.25 to 1.5 mol % in terms of Re2O3.

[0032] It is noted that same effects can be produced regardless of whether a single rare-earth element is used as in samples 43 to 53 or two or more of rare-earth elements are used together as in samples 54 to 57 as long as the above-described preferable content range of the rare-earth element Re is satisfied.

[0033] When the content of the oxide of Mg is 0 mol % in terms of MgO as in the sample 58, the tanδ thereof goes over 10.0% or capacitance variation ΔC/C20 of the produced multilayer ceramic capacitors deviates from the range from −80% to +30% when the temperature varies from −25° C. to +85° C.; whereas when the oxide of Mg is set to be 0.1 mol % in terms of MgO as in sample 59, the desired electrical characteristics can be successfully obtained.

[0034] In addition, when the content of the oxide of Mg is 0.6 mol % in terms of MgO as in the sample 61, the relative permittivity of the produced multilayer ceramic capacitors may become equal to or less than 10,000 or the capacitance variation ΔC/C20 of the produced multilayer ceramic capacitors deviates from the range from −80% to +30% when the temperature varies from −25° C. to +85° C.; and accordingly, the desired accelerated life cannot be obtained. However, when the content of the oxide of Mg is set to be 0.4 mol % in terms of MgO as in sample 60, the desired electrical characteristics can be successfully obtained.

[0035] Accordingly, the content of the oxide of Mg desirably ranges from 0.1 to 0.4 mol % in terms of MgO.

[0036] When the content of an oxide of each element Mn, V or Cr is 0.02 mol % in terms of Mn2O3, V2O5 or Cr2O3, as in the samples 1 to 3, the desired accelerated life of the produced multilayer ceramic capacitors may not be obtained; whereas when the total content of the oxides of Mn, V and Cr is set to be 0.03 mol % in terms of Mn2O3, V2O5 and Cr2O3, as in samples 4 to 6, the desired characteristics can be successfully attained.

[0037] Further, when the content of an oxide of Mn, V or Cr is 0.7 mol % in terms of Mn2O3, V2O5 or Cr2O3, as in the samples 25 to 27, the dielectric constant of the capacitors becomes equal to or less than 10,000. However, when the content of sum of the oxides of Mn, V and Cr is set to be 0.6 mol % in terms of Mn2O3, V2O5 and Cr2O3, as in samples 22 to 24, the desired characteristics can be successfully attained.

[0038] Accordingly, it is preferable that the total amount of oxides of Mn, V and Cr ranges from 0.03 to 0.6 mol % in terms of Mn2O3, V2O5 and Cr2O3.

[0039] It is to be noted that same effects can be obtained regardless of whether an oxide of one of the elements Mn, V and Cr as in samples 4 to 6 and 13 to 18 is used alone or two or more thereof are used together as in samples 7 to 12 and 19 to 24 as long as the total content thereof satisfies the above specified range.

[0040] Further, the dielectric ceramic composition in accordance with the present invention may further include one or more oxides selected from the group consisting of oxides of Fe, Ni and Cu. In this case, it is preferable that a total content of oxides of Fe, Ni, Cu, Mn, V and Cr is 0.04 to 1.0 mol %, the total content being calculated by assuming that the oxides of Fe, Ni, Cu, Mn, V and Cr are FeO, NiO, CuO, Mn2O3, V2O5 and Cr2O3, respectively.

[0041] When the content of oxides of Mo and/or W is 0 mol % in terms of MoO3 and WO3 as in the samples 29, 116 and 123, the desired operating life can not be obtained; whereas when the content of oxides of Mo and/or W is 0.02 mol % in terms of MoO3 and WO3 as in samples 30, 117 and 124, the desired electrical characteristics can be successfully obtained.

[0042] Moreover, when the content of oxides of Mo and/or W is 0.35 mol % in terms of MoO3 and WO3 as in the samples 34, 122 and 137, the tanδ thereof may be deteriorated over 10.0% and the capacitance variation ΔC/C20 exceeds the range from −80% to +30% with the temperature varying from −25° C. to +85° C. However, when the total content of oxides is set to be 0.3 mol % as in samples 33, 121 and 136, the desired electrical characteristics can be successfully obtained.

[0043] Accordingly, it is preferable that the total content of the oxides of Mo and W ranges from 0.02 to 0.3 mol % in terms of MoO3 and WO3.

[0044] Furthermore, same effects can be obtained regardless of whether the oxides of Mo and W are used separately as in the samples 30 to 33 and 117 to 121 or used together as in the samples 124 to 130 and 132 to 136.

[0045] The optimum range of the glass component varies depending on the constituents thereof.

[0046] First, in case the glass component is substantially formed of SiO2 only, the optimum content of the glass component is as follows:

[0047] When the content of SiO2 is 0.00 mol % as in the sample 111, a highly densified ceramic body may not be obtained by the sintering process at 1200° C.; whereas when the content of SiO2 is set to be 0.2 mol % as in sample 112, the desired electrical characteristics can be successfully obtained.

[0048] Further, when the content of SiO2 is 5.0 mol % as in the sample 115, the dielectric constant of the capacitors becomes equal to or less than 10,000 and accordingly the desired accelerated life may not be obtained; whereas when the content of SiO2 is set to be 4.0 mol % as in sample 114, the desired electrical characteristics can be obtained.

[0049] Accordingly, the content of the glass component mainly formed of SiO2 preferably ranges from 0.2 mol % and 4.0 mol %.

[0050] In case the glass component including SiO2 is composed of Li2O—BaO—TiO2—SiO2, the optimum range of the content of Li2O—BaO—TiO2—SiO2 preferably is determined as follows:

[0051] When the total content of glass component Li2O—BaO—TiO2—SiO2 is 0 mol % as in the sample 62, tanδ of the produced capacitor may be deteriorated over 10.0% or the desired accelerated life may not be obtained; whereas when the content of the glass component Li2O—BaO—TiO2—SiO2 is 0.05 mol % as in sample 63, the desired electrical characteristics can be successfully attained.

[0052] Further, when the content of the glass component Li2O—BaO—TiO2—SiO2 is 2.0 mol % as in the sample 66, the relative permittivity of the produced multilayer ceramic capacitor may fall below 10,000 or the desired accelerated life may not be attained; whereas when the content of the glass component Li2O—BaO—TiO2—SiO2 is 1.0 mol % as in sample 65, the desired electrical characteristics can be obtained.

[0053] Accordingly, the total content of the glass component Li2O—BaO—TiO2—SiO2 is preferably between 0.05 and 1.0 wt % inclusive.

[0054] In case the glass component including SiO2 is composed of B2O3—SiO2—MO (MO used herein represents one or more oxides selected from the group of BaO, SrO, CaO, MgO and ZnO), the preferable composition of B2O3—SiO2—MO for obtaining desired electrical characteristics is within the range surrounded by 6 lines formed by cyclically connecting 6 points A, B, C, D, E and F in that order shown in a triangular composition diagram of FIG. 2, wherein the triangular composition diagram exhibits a composition of B2O3—SiO2—MO in terms of their mol %. The first point A represents a composition containing 1 mol % of B2O3, 80 mol % of SiO2 and 19 mol % of MO, a second point B represents a composition including 1 mol % of B2O3, 39 mol % of SiO2 and 60 mol % of MO. The third point C represents a composition containing 29 mol % of B2O3, 1 mol % of SiO2 and 70 mol % of MO. The fourth point D represents a composition containing 90 mol % of B2O3, 1 mol % of SiO2 and 9 mol % of MO. The fifth point E represents a composition containing 90 mol % of B2O3, 9 mol % of SiO2 and 1 mol % of MO and the sixth point F represents a composition containing 19 mol % of B2O3, 80 mol % of SiO2 and 1 mol % of MO. If a B2O3—SiO2—Mo composition is within the range defined with 6 points described above as in samples 73, 74, 76 to 78, 80, 81 and 83, the desired electrical characteristics can be obtained. However, if the composition is out of the range as in the samples 72, 75, 79 and 82, a highly densified ceramic body may not be attained at 1200° C.

[0055] Further, when the content of B2O3—SiO2—MO is 0 wt % as in the sample 67, a highly densified ceramic body may not be obtained when sintered at 1200° C.; whereas when the content of B2O3—SiO2—Mo is 0.05 wt % as in sample 68, the desired electrical characteristics can be successfully attained.

[0056] Still further, when the content of B2O3—SiO2—Mo is 10.00 wt % as in the sample 71, the relative permittivity may become less than 10,000 or the desired accelerated life may not be obtained; whereas when the content of B2O3—SiO2—Mo is set to be 5.00 wt % as in sample 70, the desired electrical characteristics can be obtained.

[0057] Accordingly, the content of B2O3—SiO2—Mo preferably ranges from 0.05 to 5.0 wt %.

[0058] When the glass component including SiO2 is composed of Li2O—SiO2—MO (Mo used herein represents one or more oxides selected from the group consisting of BaO, SrO, CaO, MgO and ZnO), the preferable compositional range for Li2O—SiO2—MO is within the range surrounded by 6 lines formed by cyclically connecting 6 points G, H, I, J, K and L in that order as shown in a triangular composition diagram of FIG. 3, wherein the triangular diagram shows a compositional of Li2O—SiO2—MO in a unit of mol %. The seventh point G represents a composition containing 1 mol % of Li2O, 94 mol % of SiO2 and 5 mol % of MO. The eighth point H represents a composition containing 1 mol % of Li2O, 19 mol % of SiO2 and 80 mol % of MO. The ninth point I represents a composition containing 19 mol % of Li2O, 1 mol % of SiO2 and 80 mol % of MO. The tenth point J represents a composition containing 89 mol % of Li2O, 1 mol % of SiO2 and 10 mol % of MO. The eleventh point K represents a composition containing 90 mol % of Li2O3, 9 mol % of SiO2 and 1 mol % of MO and the twelfth point L represents a composition containing 5 mol % of Li2O, 94 mol % of SiO2 and 1 mol % of MO. If a Li2O—SiO2—Mo composition falls within the range defined by the 6 G-L, as in samples 144, 145, 147 to 149, 151, 152 and 154, the desired electrical characteristics can be obtained. However, if otherwise as in the samples 143, 146, 150 and 153, a highly densified ceramic body with a highly improved density may not be attained after being sintered at 1200° C. or the relative permittivity may become less than 10,000.

[0059] Further, when the content of Li2O—SiO2—MO is 0 wt % as in the sample 138, a highly densified ceramic body may not be obtained by the sintering process at 1200° C.; whereas when the content of Li2O—SiO2—MO is set as 0.05 wt % as in sample 139, the desired electrical characteristics can be acquired.

[0060] Still further, when the content of Li2O—SiO2—MO is 10.00 wt % as in the sample 142, a highly densified ceramic body may not be gained by the sintering at 1200° C.; whereas when the content of Li2O—SiO2—MO is set to be 5.00 wt % as in sample 141, the desired electrical characteristics can be successfully obtained.

[0061] Accordingly, the content of Li2O—SiO2—MO optimally ranges from 0.05 to 5.0 wt %.

[0062] When x in the oxide of Ba(Ti1−xZrx)O3 is 0.00 as in the sample 155, the desired accelerated life may not be attained; whereas when x in the oxide of Ba(Ti1−xZrx)O3 is 0.05 as in sample 156, the desired electrical characteristics can be successfully obtained.

[0063] Further, When x in the oxide of Ba(Ti1−xZrx)O3 is 0.3 as in the sample 159, the relative permittivity may become less than 10,000; whereas when x in the oxide of Ba(Ti1−xZrx)O3 is 0.26 as in the sample 158, the desired electrical characteristics can be successfully obtained.

[0064] Accordingly, it is preferable that the value of x in the oxide of Ba(Ti1−xZrx)O3 is equal to or greater than 0.05 and equal to or less than 0.26.

[0065] The present invention can produce a multilayer ceramic capacitor capable of providing a desired accelerated life with a highly improved reliability, wherein the capacitor exhibits a relative permittivity εr of 10,000 or greater, tanδ of 10.0% or less and a capacitance variation ΔC/C20 ranging from −80% to +30% with the temperature variances from −25° C. to +85° C.

[0066] It should be noted that other types of raw materials can be employed as source materials for obtaining the ceramic slurry. For instance, barium acetate or barium nitrate can be used instead of BaCO3.

[0067] Although the present invention has been described with reference to the multilayer ceramic capacitors only, it should be apparent to those skilled in the art that the present invention can also be applied to single-layer ceramic capacitors.

[0068] While the invention has been shown and described with respect to the preferred embodiments, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the following claims.

	TABLE 1-1
		content of the glass
	composition of minor additives (mol %)	component (wt %)
	Main component (mol %)	rare-earth		content
sample	composition		(Re2O3)		transition metal	total		#1	B2O3-SiO2-MO	←mol
number	Ba	Ti	Zr	Ba/(TiZr)	element	content	MgO	Mn2O3	V2O5	Cr2O3	content	MoO3	Li2O-	M	B2O3	SiO2	MO	ratio
1&Asteriskpseud;	100	86	14	1.003	Ho	1.0	0.2	0.02	—	—	0.02	0.1	0.1	—	—	—	—	—
2&Asteriskpseud;	100	86	14	1.003	Ho	1.0	0.2	—	0.02	—	0.02	0.1	0.1	—	—	—	—	—
3&Asteriskpseud;	100	86	14	1.003	Ho	1.0	0.2	—	—	0.02	0.02	0.1	0.1	—	—	—	—	—
4	100	86	14	1.003	Ho	1.0	0.2	0.03	—	—	0.03	0.1	0.1	—	—	—	—	—
5	100	86	14	1.003	Ho	1.0	0.2	—	0.03	—	0.03	0.1	0.1	—	—	—	—	—
6	100	86	14	1.003	Ho	1.0	0.2	—	—	0.03	0.03	0.1	0.1	—	—	—	—	—
7	100	86	14	1.003	Ho	1.0	0.2	0.01	0.02	—	0.03	0.1	0.1	—	—	—	—	—
8	100	86	14	1.003	Ho	1.0	0.2	0.05	0.02	—	0.07	0.1	0.1	—	—	—	—	—
9	100	86	14	1.003	Ho	1.0	0.2	0.05	—	0.1	0.15	0.1	0.1	—	—	—	—	—
10	100	86	14	1.003	Ho	1.0	0.2	0.05	0.01	0.1	0.16	0.1	0.1	—	—	—	—	—
11	100	86	14	1.003	Ho	1.0	0.2	0.1	0.05	0.1	0.25	0.1	0.1	—	—	—	—	—
12	100	86	14	1.003	Ho	1.0	0.2	0.1	0.1	0.1	0.3	0.1	0.1	—	—	—	—	—
13	100	86	14	1.003	Ho	1.0	0.2	0.3	—	—	0.3	0.1	0.1	—	—	—	—	—
14	100	86	14	1.003	Ho	1.0	0.2	—	0.3	—	0.3	0.1	0.1	—	—	—	—	—
15	100	86	14	1.003	Ho	1.0	0.2	—	—	0.3	0.3	0.1	0.1	—	—	—	—	—
16	100	86	14	1.003	Ho	1.0	0.2	0.6	—	—	0.6	0.1	0.1	—	—	—	—	—
17	100	86	14	1.003	Ho	1.0	0.2	—	0.6	—	0.6	0.1	0.1	—	—	—	—	—
18	100	86	14	1.003	Ho	1.0	0.2	—	—	0.6	0.6	0.1	0.1	—	—	—	—	—
19	100	86	14	1.003	Ho	1.0	0.2	0.3	0.3	—	0.6	0.1	0.1	—	—	—	—	—
20	100	86	14	1.003	Ho	1.0	0.2	0.3	—	0.3	0.6	0.1	0.1	—	—	—	—	—
21	100	86	14	1.003	Ho	1.0	0.2	—	0.3	0.3	0.6	0.1	0.1	—	—	—	—	—
22	100	86	14	1.003	Ho	1.0	0.2	0.2	—	0.4	0.6	0.1	0.1	—	—	—	—	—
23	100	86	14	1.003	Ho	1.0	0.2	0.1	—	0.5	0.6	0.1	0.1	—	—	—	—	—
24	100	86	14	1.003	Ho	1.0	0.2	0.2	0.2	0.2	0.6	0.1	0.1	—	—	—	—	—
25&Asteriskpseud;	100	86	14	1.003	Ho	1.0	0.2	0.7	—	—	0.7	0.1	0.1	—	—	—	—	—
26&Asteriskpseud;	100	86	14	1.003	Ho	1.0	0.2	—	0.7	—	0.7	0.1	0.1	—	—	—	—	—
27&Asteriskpseud;	100	86	14	1.003	Ho	1.0	0.2	—	—	0.7	0.7	0.1	0.1	—	—	—	—	—
28	100	86	14	1.003	Ho	1.0	0.2	0.2	0.1	0.4	0.7	0.1	0.1	—	—	—	—	—
29&Asteriskpseud;	100	86	14	1.003	Ho	1.0	0.2	0.05	0.1	0.1	0.25	0	0.1	—	—	—	—	—
Sample numbers marked with &Asteriskpseud; are comparative examples.
#1 Li2O-: Li2O-BaO-TiO2-SiO2

[0069]

	TABLE 1-2
		content of the glass
	composition of minor additives (mol %)	component (wt %)
	Main component (mol %)	rare-earth		content
sample	composition		(Re2O3)		transition metal	total		#1	B2O3-SiO2-MO	←mol
number	Ba	Ti	Zr	Ba/(TiZr)	element	content	MgO	Mn2O3	V2O5	Cr2O3	content	MoO3	Li2O-	M	B2O3	SiO2	MO	ratio
30	100.3	86	14	1.003	Ho	1.0	0.2	0.05	0.1	0.1	0.25	0.025	0.1	—	—	—	—	—
31	100.3	86	14	1.003	Ho	1.0	0.2	0.05	0.1	0.1	0.25	0.05	0.1	—	—	—	—	—
32	100.3	86	14	1.003	Ho	1.0	0.2	0.05	0.1	0.1	0.25	0.1	0.1	—	—	—	—	—
33	100.3	86	14	1.003	Ho	1.0	0.2	0.05	0.1	0.1	0.25	0.3	0.1	—	—	—	—	—
34&Asteriskpseud;	100.3	86	14	1.003	Ho	1.0	0.2	0.05	0.1	0.1	0.25	0.35	0.1	—	—	—	—	—
35	100.3	86	14	1.003	Ho	1.0	0.2	0.15	0.05	—	0.2	0.1	0.1	—	—	—	—	—
36&Asteriskpseud;	100.3	86	14	1.003	Ho	0	0.2	0.15	0.05	—	0.2	0.1	0.1	—	—	—	—	—
37	100.3	86	14	1.003	Ho	0.25	0.2	0.15	0.05	—	0.2	0.1	0.1	—	—	—	—	—
38	100.3	86	14	1.003	Ho	0.5	0.2	0.15	0.05	—	0.2	0.1	0.1	—	—	—	—	—
39	100.3	86	14	1.003	Ho	1.0	0.2	0.15	0.05	—	0.2	0.1	0.1	—	—	—	—	—
40	100.3	86	14	1.003	Ho	1.5	0.2	0.15	0.05	—	0.2	0.1	0.1	—	—	—	—	—
41&Asteriskpseud;	100.3	86	14	1.003	Ho	2.0	0.2	0.15	0.05	—	0.2	0.1	0.1	—	—	—	—	—
42&Asteriskpseud;	100.3	86	14	1.003	Ho	4.0	0.2	0.15	0.05	—	0.2	0.1	0.1	—	—	—	—	—
43	100.3	86	14	1.003	Sm	0.25	0.2	0.15	0.05	—	0.2	0.1	0.1	—	—	—	—	—
44	100.3	86	14	1.003	Sm	0.75	0.2	0.15	0.05	—	0.2	0.1	0.1	—	—	—	—	—
45	100.3	86	14	1.003	Eu	0.75	0.2	0.15	0.05	—	0.2	0.1	0.1	—	—	—	—	—
46	100.3	86	14	1.003	Gd	0.75	0.2	0.15	0.05	—	0.2	0.1	0.1	—	—	—	—	—
47	100.3	86	14	1.003	Tb	0.75	0.2	0.15	0.05	—	0.2	0.1	0.1	—	—	—	—	—
48	100.3	86	14	1.003	Dy	0.75	0.2	0.15	0.05	—	0.2	0.1	0.1	—	—	—	—	—
49	100.3	86	14	1.003	Er	0.75	0.2	0.15	0.05	—	0.2	0.1	0.1	—	—	—	—	—
50	100.3	86	14	1.003	Tm	0.75	0.2	0.15	0.05	—	0.2	0.1	0.1	—	—	—	—	—
51	100.3	86	14	1.003	Yb	0.75	0.2	0.15	0.05	—	0.2	0.1	0.1	—	—	—	—	—
52	100.3	86	14	1.003	Yb	1.0	0.2	0.15	0.05	—	0.2	0.1	0.1	—	—	—	—	—
53	100.3	86	14	1.003	Y	1.0	0.2	0.15	0.05	—	0.2	0.1	0.1	—	—	—	—	—
54	100.3	86	14	1.003	Ho/Dy	0.5/0.5	0.2	0.15	0.05	—	0.2	0.1	0.1	—	—	—	—	—
55	100.3	86	14	1.003	Ho/Dy/Yb	5/0.5/0.	0.2	0.15	0.05	—	0.2	0.1	0.1	—	—	—	—	—
56	100.3	86	14	1.003	Sm/Ho/Yb	2/0.5/0.	0.2	0.15	0.05	—	0.2	0.1	0.1	—	—	—	—	—
57	100.3	86	14	1.003	Sm/Yb	0.5/1.0	0.2	0.15	0.05	—	0.2	0.1	0.1	—	—	—	—	—
58&Asteriskpseud;	100.3	86	14	1.003	Ho	1	0	0.15	0.05	—	0.2	0.1	0.1	—	—	—	—	—
Sample numbers marked with &Asteriskpseud; are comparative examples.
#1 Li2O-: Li2O-BaO-TiO2-SiO2

[0070]

	TABLE 1-3
		content of the glass
	composition of minor additives (mol %)	component (wt %)
	Main component (mol %)	rare-earth		content
sample	composition		(Re2O3)		transition metal	total		#1	B2O3-SiO2-MO	←mol
number	Ba	Ti	Zr	Ba/(TiZr)	element	content	MgO	Mn2O3	V2O5	Cr2O3	content	MoO3	Li2O-	M	B2O3	SiO2	MO	ratio
59	100.3	86	14	1.003	Ho	1	0.1	0.15	0.05	—	0.2	0.1	0.1	—	—	—	—	—
60	100.3	86	14	1.003	Ho	1	0.4	0.15	0.05	—	0.2	0.1	0.1	—	—	—	—	—
61&Asteriskpseud;	100.3	86	14	1.003	Ho	1	0.6	0.15	0.05	—	0.2	0.1	0.1	—	—	—	—	—
62&Asteriskpseud;	100.3	86	14	1.003	Ho	1	0.2	0.15	0.05	—	0.2	0.1	0	—	—	—	—	—
63	100.3	86	14	1.003	Ho	1	0.2	0.15	0.05	—	0.2	0.1	0.05	—	—	—	—	—
64	100.3	86	14	1.003	Ho	1	0.2	0.15	0.05	—	0.2	0.1	0.5	—	—	—	—	—
65	100.3	86	14	1.003	Ho	1	0.2	0.15	0.05	—	0.2	1.1	1	—	—	—	—	—
66&Asteriskpseud;	100.3	86	14	1.003	Ho	1	0.2	0.15	0.05	—	0.2	2.1	2	—	—	—	—	—
67&Asteriskpseud;	100.3	86	14	1.003	Ho	1	0.2	0.15	0.05	0.2	0.4	0.05	—	Ca	15	65	20	0.00
68	100.3	86	14	1.003	Ho	1	0.2	0.15	0.05	0.2	0.4	0.05	—	Ca	15	65	20	0.05
69	100.3	86	14	1.003	Ho	1	0.2	0.15	0.05	0.2	0.4	0.05	—	Ca	15	65	20	2.00
70	100.3	86	14	1.003	Ho	1	0.2	0.15	0.05	0.2	0.4	0.05	—	Ca	15	65	20	5.00
71&Asteriskpseud;	100.3	86	14	1.003	Ho	1	0.2	0.15	0.05	0.2	0.4	0.05	—	Ca	15	65	20	10.00
72&Asteriskpseud;	100.3	86	14	1.003	Ho	1	0.2	0.15	0.05	0.2	0.4	0.05	—	Ca	95	4	1	1.00
73	100.3	86	14	1.003	Ho	1	0.2	0.15	0.05	0.2	0.4	0.05	—	Ca	90	9	1	1.00
74	100.3	86	14	1.003	Ho	1	0.2	0.15	0.05	0.2	0.4	0.05	—	Ca	90	1	9	1.00
75&Asteriskpseud;	100.3	86	14	1.003	Ho	1	0.2	0.15	0.05	0.2	0.4	0.05	—	Ca	50	50	0	1.00
76	100.3	86	14	1.003	Ho	1	0.2	0.15	0.05	0.2	0.4	0.05	—	Ca	20	70	10	1.00
77	100.3	86	14	1.003	Ho	1	0.2	0.15	0.05	0.2	0.4	0.05	—	Ca	19	80	1	1.00
78	100.3	86	14	1.003	Ho	1	0.2	0.15	0.05	0.2	0.4	0.05	—	Ca	1	80	19	1.00
79&Asteriskpseud;	100.3	86	14	1.003	Ho	1	0.2	0.15	0.05	0.2	0.4	0.05	—	Ca	4	95	1	1.00
80	100.3	86	14	1.003	Ho	1	0.2	0.15	0.05	0.2	0.4	0.05	—	Ca	1	39	60	1.00
81	100.3	86	14	1.003	Ho	1	0.2	0.15	0.05	0.2	0.4	0.05	—	Ca	29	1	70	1.00
82&Asteriskpseud;	100.3	86	14	1.003	Ho	1	0.2	0.15	0.05	0.2	0.4	0.05	—	Ca	4	5	95	1.00
83	100.3	86	14	1.003	Ho	1	0.2	0.15	0.05	0.2	0.4	0.05	—	Ca	20	30	50	1.00
Sample numbers marked with &Asteriskpseud; are comparative examples.
#1 Li2O-: Li2O-BaO-TiO2-SiO2

[0071]

	TABLE 1-4
		content of the glass
	composition of minor additives (mol %)	component (wt %)
	Main component (mol %)	rare-earth		content
sample	composition		(Re2O3)		transition metal	total		#1	B2O3-SiO2-MO	←mol
number	Ba	Ti	Zr	Ba/(TiZr)	element	content	MgO	Mn2O3	V2O5	Cr2O3	content	MoO3	Li2O-	M	B2O3	SiO2	MO	ratio
84&Asteriskpseud;	100.3	86	14	1.003	Ho	1.0	0.2	0.02	—	—	0.02	0.05	0.05	0.1	Ba	15	20	1.00
85&Asteriskpseud;	100.3	86	14	1.003	Ho	1.0	0.2	—	0.02	—	0.02	0.05	0.05	0.1	Ba	15	20	1.00
86&Asteriskpseud;	100.3	86	14	1.003	Ho	1.0	0.2	—	—	0.02	0.02	0.05	0.05	0.1	Ba	15	20	1.00
87	100.3	86	14	1.003	Ho	1.0	0.2	0.03	—	—	0.03	0.05	0.05	0.1	Ca	15	20	1.00
88	100.3	86	14	1.003	Ho	1.0	0.2	—	0.03	—	0.03	0.05	0.05	0.1	Ca	15	20	1.00
89	100.3	86	14	1.003	Ho	1.0	0.2	—	—	0.03	0.03	0.05	0.05	0.1	Ca	15	20	1.00
90	100.3	86	14	1.003	Ho	1.0	0.2	0.01	0.02	—	0.03	0.05	0.05	0.1	Sr	15	20	1.00
91	100.3	86	14	1.003	Ho	1.0	0.2	0.05	0.02	—	0.07	0.05	0.05	0.1	Sr	15	20	1.00
92	100.3	86	14	1.003	Ho	1.0	0.2	0.05	—	0.1	0.15	0.05	0.05	0.1	Sr	15	20	1.00
93	100.3	86	14	1.003	Ho	1.0	0.2	0.05	0.01	0.1	0.16	0.05	0.05	0.1	Sr	15	20	1.00
94	100.3	86	14	1.003	Ho	1.0	0.2	0.1	0.05	0.1	0.25	0.05	0.05	0.1	Mg	15	20	1.00
95	100.3	86	14	1.003	Ho	1.0	0.2	0.1	0.1	0.1	0.3	0.05	0.05	0.1	Mg	15	20	1.00
96	100.3	86	14	1.003	Ho	1.0	0.2	0.3	—	—	0.3	0.05	0.05	0.1	Mg	15	20	1.00
97	100.3	86	14	1.003	Ho	1.0	0.2	—	0.3	—	0.3	0.05	0.05	0.1	Mg	15	20	1.00
98	100.3	86	14	1.003	Ho	1.0	0.2	—	—	0.3	0.3	0.05	0.05	0.1	Mg	15	20	1.00
99	100.3	86	14	1.003	Ho	1.0	0.2	0.6	—	—	0.6	0.05	0.05	0.1	Zn	15	20	1.00
100	100.3	86	14	1.003	Ho	1.0	0.2	—	0.6	—	0.6	0.05	0.05	0.1	Zn	15	20	1.00
101	100.3	86	14	1.003	Ho	1.0	0.2	—	—	0.6	0.6	0.05	0.05	0.1	Zn	15	20	1.00
102	100.3	86	14	1.003	Ho	1.0	0.2	0.3	0.3	—	0.6	0.05	0.05	0.1	Ba	15	20	1.00
103	100.3	86	14	1.003	Ho	1.0	0.2	0.3	—	0.3	0.6	0.05	0.05	0.1	Ba	15	20	1.00
104	100.3	86	14	1.003	Ho	1.0	0.2	—	0.3	0.3	0.6	0.05	0.05	0.1	Ba	15	20	1.00
105	100.3	86	14	1.003	Ho	1.0	0.2	0.2	—	0.4	0.6	0.05	0.05	0.1	Ba	15	20	1.00
106	100.3	86	14	1.003	Ho	1.0	0.2	0.1	—	0.5	0.6	0.05	0.05	0.1	Ba	15	20	1.00
107	100.3	86	14	1.003	Ho	1.0	0.2	0.2	0.2	0.2	0.6	0.05	0.05	0.1	Ba	15	20	1.00
108&Asteriskpseud;	100.3	86	14	1.003	Ho	1.0	0.2	0.7	—	—	0.7	0.05	0.05	0.1	Ba/Ca	15	20	1.00
109&Asteriskpseud;	100.3	86	14	1.003	Ho	1.0	0.2	—	0.7	—	0.7	0.05	0.05	0.1	Ba/Ca	15	20	1.00
110&Asteriskpseud;	100.3	86	14	1.003	Ho	1.0	0.2	—	—	0.7	0.7	0.05	0.05	0.1	Ba/Ca	15	20	1.00
Sample numbers marked with &Asteriskpseud; are comparative examples.
#1 Li2O-: Li2O-BaO-TiO2-SiO2

[0072]

	TABLE 1-5
	composition of minor additives (mol %)
	main component (mol %)	rare-earth
sample	composition		(Re2O3)		transition metal	total		total	(wt %)
number	Ba	Ti	Zr	Ba/(TiZr)	element	content	MgO	Mn2O3	V2O5	Cr2O3	content	MoO3	WO3	content	SiO2
111&Asteriskpseud;	100.3	86	14	1.003	Ho	1.0	0.2	0.15	0.05	—	0.2	0.05	0.05	0.1	0
112	100.3	86	14	1.003	Ho	1.0	0.2	0.15	0.05	—	0.2	0.05	0.05	0.1	0.2
113	100.3	86	14	1.003	Ho	1.0	0.2	0.15	0.05	—	0.2	0.05	0.05	0.1	1
114	100.3	86	14	1.003	Ho	1.0	0.2	0.15	0.05	—	0.2	0.05	0.05	0.1	4
115&Asteriskpseud;	100.3	86	14	1.003	Ho	1.0	0.2	0.15	0.05	—	0.2	0.05	0.05	0.1	5
116&Asteriskpseud;	100.3	86	14	1.003	Ho	1.0	0.2	0.05	0.1	—	0.15	—	0	0	—
117	100.3	86	14	1.003	Ho	1.0	0.2	0.05	0.1	—	0.15	—	0.025	0.025	—
118	100.3	86	14	1.003	Ho	1.0	0.2	0.05	0.1	—	0.15	—	0.05	0.05	—
119	100.3	86	14	1.003	Ho	1.0	0.2	0.05	0.1	—	0.15	—	0.1	0.1	—
120	100.3	86	14	1.003	Ho	1.0	0.2	0.05	0.1	—	0.15	—	0.2	0.2	—
121	100.3	86	14	1.003	Ho	1.0	0.2	0.05	0.1	—	0.15	—	0.3	0.3	—
122&Asteriskpseud;	100.3	86	14	1.003	Ho	1.0	0.2	0.05	0.1	—	0.15	—	0.35	0.35	—
123&Asteriskpseud;	100.3	86	14	1.003	Ho	1.0	0.2	0.05	0.1	—	0.15	0	0	0	—
124	100.3	86	14	1.003	Ho	1.0	0.2	0.05	0.1	—	0.15	0.01	0.01	0.02	—
125	100.3	86	14	1.003	Ho	1.0	0.2	0.05	0.1	—	0.15	0.02	0.02	0.04	—
126	100.3	86	14	1.003	Ho	1.0	0.2	0.05	0.1	—	0.15	0	0.05	0.05	—
127	100.3	86	14	1.003	Ho	1.0	0.2	0.05	0.1	—	0.15	0.025	0.05	0.075	—
128	100.3	86	14	1.003	Ho	1.0	0.2	0.05	0.1	—	0.15	0.05	0.05	0.1	—
129	100.3	86	14	1.003	Ho	1.0	0.2	0.05	0.1	—	0.15	0.1	0.05	0.15	—
130	100.3	86	14	1.003	Ho	1.0	0.2	0.05	0.1	—	0.15	0.2	0.05	0.25	—
131&Asteriskpseud;	100.3	86	14	1.003	Ho	1.0	0.2	0.05	0.1	—	0.15	0.3	0.05	0.35	—
132	100.3	86	14	1.003	Ho	1.0	0.2	0.05	0.1	—	0.15	0.05	0	0.05	—
133	100.3	86	14	1.003	Ho	1.0	0.2	0.05	0.1	—	0.15	0.05	0.025	0.075	—
134	100.3	86	14	1.003	Ho	1.0	0.2	0.05	0.1	—	0.15	0.05	0.05	0.1	—
135	100.3	86	14	1.003	Ho	1.0	0.2	0.05	0.1	—	0.15	0.05	0.1	0.15	—
136	100.3	86	14	1.003	Ho	1.0	0.2	0.05	0.1	—	0.15	0.05	0.2	0.25	—
137&Asteriskpseud;	100.3	86	14	1.003	Ho	1.0	0.2	0.05	0.1	—	0.15	0.05	0.3	0.35	—
Sample numbers marked with &Asteriskpseud; are comparative examples.

[0073]

	TABLE 1-6
			content of the glass component
	main component	composition of minor additives (mol %)	(wt %)
	(mol %)	rare-earth		content		content
sample	composition	Ba/	(Re2O3)		transition metal	total		←mol	B2O3-SiO2-MO	←mol
number	Ba	Ti	Zr	(TiZr)	element	content	MgO	Mn2O3	V2O5	Cr2O3	content	MoO3	WO3	ratio	M	B2O3	SiO2	MO	ratio
138&Asteriskpseud;	100.3	86	14	1.003	Ho	1.0	0.2	0.15	0.05	—	0.2	0.05	0.05	0.1	Ca	15	65	20	0.00
139	100.3	86	14	1.003	Ho	1.0	0.2	0.15	0.05	—	0.2	0.05	0.05	0.1	Ca	15	65	20	0.05
140	100.3	86	14	1.003	Ho	1.0	0.2	0.15	0.05	—	0.2	0.05	0.05	0.1	Ca	15	65	20	2.00
141	100.3	86	14	1.003	Ho	1.0	0.2	0.15	0.05	—	0.2	0.05	0.05	0.1	Ca	15	65	20	5.00
142&Asteriskpseud;	100.3	86	14	1.003	Ho	1.0	0.2	0.15	0.05	—	0.2	0.05	0.05	0.1	Ca	15	65	20	10.00
143&Asteriskpseud;	100.3	86	14	1.003	Ho	1.0	0.2	0.15	0.05	—	0.2	0.05	0.05	0.1	Ca	95	4	1	1.00
144	100.3	86	14	1.003	Ho	1.0	0.2	0.15	0.05	—	0.2	0.05	0.05	0.1	Ca	90	9	1	1.00
145	100.3	86	14	1.003	Ho	1.0	0.2	0.15	0.05	—	0.2	0.05	0.05	0.1	Ca	89	1	10	1.00
146&Asteriskpseud;	100.3	86	14	1.003	Ho	1.0	0.2	0.15	0.05	—	0.2	0.05	0.05	0.1	Ca	50	50	0	1.00
147	100.3	86	14	1.003	Ho	1.0	0.2	0.15	0.05	—	0.2	0.05	0.05	0.1	Ca	20	70	10	1.00
148	100.3	86	14	1.003	Ho	1.0	0.2	0.15	0.05	—	0.2	0.05	0.05	0.1	Ca	5	94	1	1.00
149	100.3	86	14	1.003	Ho	1.0	0.2	0.15	0.05	—	0.2	0.05	0.05	0.1	Ca	1	94	5	1.00
150&Asteriskpseud;	100.3	86	14	1.003	Ho	1.0	0.2	0.15	0.05	—	0.2	0.05	0.05	0.1	Ca	4	95	1	1.00
151	100.3	86	14	1.003	Ho	1.0	0.2	0.15	0.05	—	0.2	0.05	0.05	0.1	Ca	1	79	20	1.00
152	100.3	86	14	1.003	Ho	1.0	0.2	0.15	0.05	—	0.2	0.05	0.05	0.1	Ca	19	1	80	1.00
153&Asteriskpseud;	100.3	86	14	1.003	Ho	1.0	0.2	0.15	0.05	—	0.2	0.05	0.05	0.1	Ca	4	5	95	1.00
154	100.3	86	14	1.003	Ho	1.0	0.2	0.15	0.05	—	0.2	0.05	0.05	0.1	Ca	20	30	50	1.00
155&Asteriskpseud;	100.5	100	0	1.005	Ho	1.0	0.2	0.15	0.05	—	0.2	0.05	0.05	0.1	Ca	20	30	50	1.00
156	100.5	95	5	1.005	Ho	1.0	0.2	0.15	0.05	—	0.2	0.05	0.05	0.1	Ca	20	30	50	1.00
157	100.5	80	20	1.005	Ho	1.0	0.2	0.15	0.05	—	0.2	0.05	0.05	0.1	Ca	20	30	50	1.00
158	100.5	74	26	1.005	Ho	1.0	0.2	0.15	0.05	—	0.2	0.05	0.05	0.1	Ca	20	30	50	1.00
159&Asteriskpseud;	100.5	70	30	1.005	Ho	1.0	0.2	0.15	0.05	—	0.2	0.05	0.05	0.1	Ca	20	30	50	1.00
Sample numbers marked with &Asteriskpseud; are comparative examples.

[0074]

TABLE 2-1
					capacitance
sample	sintering		tanδ	resistivity(Ω · cm) at room	variation(ΔC/ΔC20, %)	accelerated
number	temperature (° C.)	permittivity	(%)	temperature	−25° C.	+85° C.	life(sec)
1&Asteriskpseud;	1200	13099	7.32	8.85E + 12	−42.2	−68.3	127865
2&Asteriskpseud;	1200	15463	8.50	2.28E + 12	−40.8	−70.2	67865
3&Asteriskpseud;	1200	11498	7.64	4.37E + 12	−41.0	−72.6	157654
4	1200	11233	6.68	1.12E + 13	−43.7	−73.4	467600
5	1200	14455	7.03	9.68E + 12	−43.7	−71.6	497600
6	1200	13023	5.72	6.50E + 12	−43.2	−68.4	402800
7	1200	15703	5.92	6.01E + 12	−40.1	−72.7	444200
8	1200	13693	7.03	7.39E + 12	−43.3	−76.3	417800
9	1200	11833	6.79	3.37E + 12	−41.5	−76.9	341900
10	1200	12856	6.12	1.18E + 13	−42.4	−68.4	282500
11	1200	14985	5.68	5.32E + 12	−41.4	−74.6	359900
12	1200	13913	5.62	1.02E + 13	−43.1	−73.2	468200
13	1200	14123	8.28	9.13E + 12	−41.6	−69.5	437000
14	1200	15088	6.91	1.03E + 13	−41.5	−69.2	498800
15	1200	12531	5.11	8.93E + 12	−43.8	−73.5	448700
16	1200	14346	7.23	2.46E + 12	−41.5	−69.2	363500
17	1200	12689	5.57	4.71E + 12	−40.3	−69.6	374000
18	1200	15769	7.50	1.09E + 13	−41.0	−73.5	239600
19	1200	15674	6.02	2.86E + 12	−42.9	−67.3	358700
20	1200	12688	8.98	8.06E + 12	−42.4	−77.0	241100
21	1200	12655	8.51	3.18E + 12	−40.3	−68.7	426500
22	1200	15763	8.96	8.99E + 12	−41.3	−77.0	342500
23	1200	14045	7.83	8.92E + 12	−41.7	−76.7	245600
24	1200	11229	5.19	6.13E + 12	−43.2	−71.7	482900
25&Asteriskpseud;	1200	8654	5.54	5.94E + 12	−40.6	−71.7	464000
26&Asteriskpseud;	1200	6543	6.05	1.17E + 13	−42.1	−67.4	455600
27&Asteriskpseud;	1200	7698	6.17	6.36E + 12	−40.6	−74.9	86432
28	1200	12612	5.52	9.11E + 12	−43.0	−74.9	303200
29&Asteriskpseud;	1200	13498	6.48	5.75E + 12	−41.5	−67.3	134242
Sample numbers marked with &Asteriskpseud; are comparative examples.

[0075]

TABLE 2-2
					capacitance
sample	sintering		tanδ	resistivity(Ω · cm) at room	variation(ΔC/ΔC20, %)	accelerated
number	temperature (° C.)	permittivity	(%)	temperature	−25° C.	+85° C.	life(sec)
31	1200	13422	6.06	3.56E + 12	−42.2	−72.0	351200
32	1200	12846	7.28	6.21E + 12	−40.6	−68.2	362600
33	1200	15962	8.28	2,13E + 12	−42.9	−72.2	472700
34&Asteriskpseud;	1200	11320	12.30	3.81E + 12	−40.9	−67.1	237500
35	1200	11439	6.04	1.19E + 13	−43.5	−67.9	358100
36&Asteriskpseud;	1200	14038	11.90	8.58E + 12	−43.1	−84.2	494600
37	1200	15633	5.45	5.78E + 12	−42.0	−72.3	364400
38	1200	13383	5.84	1.11E + 13	−41.7	−70.7	228500
39	1200	13750	5.01	9.38E + 12	−44.0	−78.5	294200
40	1200	12731	6.14	1.15E + 13	−42.8	−68.8	298700
41&Asteriskpseud;	1200	incapable of obtaining a sintered ceramic with high density
42&Asteriskpseud;	1200	incapable of obtaining a sintered ceramic with high density
43	1200	15648	8.33	1.13E + 13	−41.6	−73.3	484700
44	1200	12850	8.91	4.13E + 12	−42.4	−72.7	356900
45	1200	14909	8.16	7,33E + 12	−41.8	−76.9	429500
46	1200	13518	6.04	4.59E + 12	−40.4	−77.4	390200
47	1200	15901	7.74	9.84E + 12	−40.7	−67.3	391700
48	1200	11935	6.32	8.41E + 12	−43.1	−74.0	450800
49	1200	12972	8.73	1.08E + 13	−43.1	−67.6	433100
50	1200	12213	5.08	5.45E + 12	−43.6	−76.5	438200
51	1200	14480	7.04	6.96E + 12	−41.3	−70.0	271400
52	1200	12133	5.32	3.31E + 12	−41.6	−78.9	353600
53	1200	11208	8.76	9.45E + 12	−43.4	−69.1	453500
54	1200	11949	7.42	1.14E + 13	−41.2	−77.5	314000
55	1200	14032	5.53	8.56E + 12	−40.7	−76.9	374000
56	1200	15576	5.28	4.31E + 12	−40.9	−78.2	378800
57	1200	14391	8.19	9.71E + 12	−42.2	−73.0	214400
58&Asteriskpseud;	1200	23129	16.80	2.38E + 12	−87.9	−67.5	454700
Sample numbers marked with &Asteriskpseud; are comparative examples.

[0076]

TABLE 2-3
					capacitance
sample	sintering		tanδ	resistivity(Ω · cm) at room	variation(ΔC/ΔC20, %)	accelerated
number	temperature (° C.)	permittivity	(%)	temperature	−25° C.	+85° C.	life(sec)
59	1200	14382	8.58	7.18E + 12	−41.4	−71.6	473900
60	1200	15968	8.96	6.33E + 12	−40.8	−75.2	334100
61&Asteriskpseud;	1200	8769	3.80	2.27E + 12	−42.7	−83.9	109886
62&Asteriskpseud;	1200	12588	13.10	3.73E + 12	−41.1	−74.0	76432
63	1200	13752	5.19	4.84E + 12	−43.1	−68.2	275000
64	1200	15777	8.25	9.00E + 12	−41.2	−69.3	430400
65	1200	12670	6.18	5.67E + 12	−42.9	−70.2	335000
66&Asteriskpseud;	1200	8438	5.81	9.13E + 12	−42.5	−78.8	5326
67&Asteriskpseud;	1200	incapable of obtaining a sintered ceramic with high density
68	1200	12238	8.24	9.18E + 12	−40.2	−70.4	218600
69	1200	11588	7.84	8.62E + 12	−43.0	−69.3	220100
70	1200	15311	6.23	6.42E + 12	−40.1	−70.7	209000
71&Asteriskpseud;	1200	5988	4.10	6.84E + 12	−40.6	−76.4	7621
72&Asteriskpseud;	1200	incapable of obtaining a sintered ceramic with high density
73	1200	15494	7.95	4.80E + 12	−42.6	−75.9	478400
74	1200	11922	7.28	6.91E + 12	−41.4	−67.8	339800
75&Asteriskpseud;	1200	incapable of obtaining a sintered ceramic with high density
76	1200	15650	5.88	3.79E + 12	−42.5	−75.5	446600
77	1200	12793	8.01	1.04E + 13	−41.7	−73.5	458600
78	1200	13733	5.53	5.32E + 12	−42.2	−70.5	341000
79&Asteriskpseud;	1200	incapable of obtaining a sintered ceramic with high density
80	1200	12016	5.22	2.37E + 12	−42.1	−68.3	443000
81	1200	14720	5.58	8.02E + 12	−41.9	−68.7	223100
82&Asteriskpseud;	1200	incapable of obtaining a sintered ceramic with high density
83	1200	12815	8.75	5.99E + 12	−40.6	−77.5	435800
Sample numbers marked with &Asteriskpseud; are comparative examples.

[0077]

TABLE 2-4
					capacitance
sample	sintering		tanδ	resistivity(Ω · cm) at room	variation(ΔC/ΔC20, %)	accelerated
number	temperature (° C.)	permittivity	(%)	temperature	−25° C.	+85° C.	life(sec)
84&Asteriskpseud;	1200	15453	8.20	9.87E + 12	−40.3	−78.5	7534
85&Asteriskpseud;	1200	11309	7.97	7.07E + 12	−42.3	−74.6	24546
86&Asteriskpseud;	1200	13496	7.36	2.21E + 12	−41.4	−77.7	6435
87	1200	15088	7.02	4.57E + 12	−40.6	−71.4	461900
88	1200	14189	7.26	9.36E + 12	−42.3	−72.4	261800
89	1200	15832	7.01	1.18E + 13	−41.4	−79.0	451700
90	1200	14417	6.16	7.57E + 12	−42.8	−67.7	239900
91	1200	14733	5.92	1.OOE + 13	−40.6	−73.0	469400
92	1200	14194	7.84	2.06E + 12	−43.7	−71.0	374000
93	1200	14177	6.43	4.81E + 12	−43.5	−67.1	412400
94	1200	15779	5.68	4.99E + 12	−40.3	−71.6	366500
95	1200	14209	8.93	1.18E + 13	−43.6	−73.5	376700
96	1200	14727	8.85	1.18E + 13	−41.4	−67.7	366800
97	1200	12523	7.34	8.38E + 12	−40.3	−72.4	247000
98	1200	11089	8.54	7.97E + 12	−40.2	−71.9	348500
99	1200	13442	7.80	2.54E + 12	−43.5	−68.5	256700
100	1200	15667	6.21	7.94E + 12	−42.2	−77.4	486500
101	1200	12847	8.47	3.12E + 12	−40.2	−68.2	407000
102	1200	12266	8.72	3.59E + 12	−43.5	−75.8	427400
103	1200	14965	8.79	8.53E + 12	−43.8	−69.0	362600
104	1200	12794	8.60	9.62E + 12	−41.1	−78.8	292100
105	1200	13163	7.96	1.13E + 13	−43.4	−72.9	315200
106	1200	12545	6.63	6.17E + 12	−41.9	−75.7	417800
107	1200	11027	5.57	6.52E + 12	−42.9	−67.6	255200
108&Asteriskpseud;	1200	7259	5.12	4.80E + 12	−40.1	−73.7	235700
109&Asteriskpseud;	1200	6439	3.53	5.37E + 12	−41.5	−70.8	369500
110&Asteriskpseud;	1200	2543	2.76	4.09E + 12	−41.5	−70.3	43455
Sample numbers marked with &Asteriskpseud; are comparative examples.

[0078]

TABLE 2-5
					capacitance
sample	sintering		tanδ	resistivity(Ω · cm) at room	variation(ΔC/ΔC20, %)	accelerated
number	temperature(° C.)	permittivity	(%)	temperature	−25° C.	+85° C.	life(sec)
111&Asteriskpseud;	1200	incapable of obtaining a sintered ceramic with high density
112	1200	11542	5.28	7.42E + 12	−43.5	−76.0	342500
113	1200	12319	5.78	1.15E + 13	−40.5	−71.2	455900
114	1200	15522	8.16	8.41E + 12	−40.1	−76.5	382100
115&Asteriskpseud;	1200	8134	2.88	5.08E + 12	−42.6	−72.9	25442
116&Asteriskpseud;	1200	18751	6.19	5.44E + 12	−40.6	−89.4	43676
117	1200	14498	7.00	1.01E + 13	−43.8	−67.3	291200
118	1200	15720	7.15	1.15E + 13	−41.0	−70.1	409700
119	1200	11067	6.45	5.03E + 12	−43.7	−70.9	377300
120	1200	14148	5.95	1.10E + 13	−40.5	−72.2	353900
121	1200	14509	6.22	2.45E + 12	−41.0	−76.7	410900
122&Asteriskpseud;	1200	20862	12.40	1.11E + 13	−86.3	−43.8	406100
123&Asteriskpseud;	1200	13545	8.80	4.33E + 12	−42.1	−70.7	36532
124	1200	14716	5.59	5.64E + 12	−43.0	−68.7	337100
125	1200	11704	7.24	5.09E + 12	−43.1	−73.8	315200
126	1200	12301	8.39	1.01E + 13	−42.8	−68.9	363200
127	1200	15933	8.23	5.32E + 12	−41.7	−72.9	239900
128	1200	13212	8.17	5.92E + 12	−43.3	−71.0	492500
129	1200	13096	8.58	6.45E + 12	−40.8	−71.4	244700
130	1200	11101	8.51	4.01E + 12	−42.0	−77.5	266000
131&Asteriskpseud;	1200	23786	15.80	2.27E + 12	−82.0	−41.9	223700
132	1200	11292	5.65	4.01E + 12	−43.6	−77.6	401600
133	1200	11672	8.67	1.10E + 13	−42.1	−68.2	361400
134	1200	12236	7.80	1.14E + 13	−42.6	−71.2	489500
135	1200	11682	8.57	1.11E + 13	−42.4	−77.9	411500
136	1200	11435	5.34	5.26E + 12	−43.0	−71.1	486800
137&Asteriskpseud;	1200	28765	17.30	9.26E + 12	−43.1	−67.4	274100
Sample numbers marked with &Asteriskpseud; are comparative examples.

[0079]

TABLE 2-6
					capacitance
sample	sintering		tanδ	resistivity(Ω · cm) at room	variation(ΔC/ΔC20, %)	accelerated
number	temperature(° C.)	permittivity	(%)	temperature	−25° C.	+85° C.	life(sec)
138&Asteriskpseud;	1200	incapable of obtaining a sintered ceramic with high density
139	1200	14744	8.85	6.46E + 12	−42.3	−76.7	394400
140	1200	12027	8.98	6.66E + 12	−42.4	−69.7	276500
141	1200	13352	6.43	1.19E + 13	−40.4	−68.5	467900
142&Asteriskpseud;	1200	incapable of obtaining a sintered ceramic with high density
143&Asteriskpseud;	1200	7612	2.98	8.92E + 12	−42.5	−74.4	2362
144	1200	11359	8.96	5.98E + 12	−41.8	−68.7	458000
145	1200	11423	8.81	6.07E + 12	−43.9	−70.3	331400
146&Asteriskpseud;	1200	incapable of obtaining a sintered ceramic with high density
147	1200	12283	7.34	2.04E + 12	−41.2	−78.6	209600
148	1200	13395	8.17	7.14E + 12	−40.9	−68.3	264500
149	1200	13730	5.70	6.00E + 12	−43.0	−76.4	372500
150&Asteriskpseud;	1200	incapable of obtaining a sintered ceramic with high density
151	1200	15706	5.27	3.93E + 12	−41.2	−72.4	283400
152	1200	13012	8.55	8.39E + 12	−43.0	−71.3	360200
153&Asteriskpseud;	1200	incapable of obtaining a sintered ceramic with high density
154	1200	14940	7.43	6.34E + 12	−40.5	−67.4	380300
155&Asteriskpseud;	1200	16485	5.68	8.84E + 12	−43.3	−68.6	12083
156	1200	14274	7.39	5.67E + 12	−40.5	−78.0	250700
157	1200	12831	6.37	5.09E + 12	−43.9	−74.0	431300
158	1200	12802	7.68	9.38E + 12	−41.7	−70.1	362300
159&Asteriskpseud;	1200	7524	8.39	7.21E + 12	−40.3	−72.7	344000
Sample numbers marked with &Asteriskpseud; are comparative examples.

Claims

1. A dielectric ceramic composition comprising: 100 mol % of an oxide of Ba, Ti and Zr, the content of the oxide of the Ba, Ti and Zr being calculated by assuming that the oxide thereof is Ba(Ti1−xZrx)O3; 0.25 to 1.5 mol % of an oxide of Re, Re representing one or more elements selected from the group consisting of Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Y, the content of the oxide of the Re being calculated by assuming that the oxide thereof is Re2O3; 0.1 to 0.4 mol % of an oxide of Mg, the content of the oxide of the Mg being calculated by assuming that the oxide thereof is MgO; 0.03 to 0.6 mol % of oxides of one or more elements selected from the group consisting of Mn, V and Cr, the contents of the oxides of the Mn, V and Cr being calculated by assuming that the oxides thereof are Mn2O3, V2O5 and Cr2O3, respectively; 0.02 to 0.3 mol % of oxides of one or two elements of Mo and W, the contents of the oxides of Mo and W being calculated by assuming that the oxides thereof Mo3O3, WO3, respectively; and a glass component including SiO2, wherein x in the oxide of Ba(Ti1−xZrx)O3 ranges from about 0.05 to about 0.26.

2. The dielectric ceramic composition of claim 1, wherein the glass component is composed of Li2O—BaO—TiO2—SiO2 and the content thereof ranges from 0.05 to 1.0 wt %.

3. The dielectric ceramic composition of claim 1, wherein the glass component is composed of B2O3—SiO2—MO, MO representing one or more oxides selected from the group consisting of BaO, SrO, CaO, MgO and ZnO, and wherein a composition of B2O3—SiO2—MO is within a range surrounded by 6 lines formed by cyclically connecting 6 points A, B, C, D, E and F in that order in a triangular composition diagram exhibiting compositional amounts of B2O3, SiO2 and Mo in a unit of mol %, and wherein a point A represents a composition including 1 mol % of B2O3, 80 mol % of SiO2 and 19 mol % of MO, a point B represents a composition including 1 mol % of B2O3, 39 mol % of SiO2 and 60 mol % of MO, a point C represents a composition including 29 mol % of B2O3, 1 mol % of SiO2 and 70 mol % of MO, a point D represents a composition including 90 mol % of B2O3, 1 mol % of SiO2 and 9 mol % of MO, a point E represents a composition including 90 mol % of B2O3, 9 mol % of SiO2 and 1 mol % of MO and a point F represents a composition including 19 mol % of B2O3, 80 mol % of SiO2 and 1 mol % of MO, a content of the composition B2O3—SiO2—MO ranging from 0.05 to 5.0 wt %.

4. The dielectric ceramic composition of claim 1, wherein the glass component is substantially composed of SiO2 and a content thereof is 0.20 to 4.0 mol %.

5. The dielectric ceramic composition of claim 1, wherein the glass component is composed of Li2O—SiO2—MO, MO representing one or more oxides selected from the group consisting of BaO, SrO, CaO, MgO and ZnO, and wherein the composition of Li2O—SiO2—MO is within a range surrounded by 6 lines formed by cyclically connecting 6 points G, H, I, J, K and L in that order in a triangular composition diagram showing compositional amounts of Li2O, SiO2 and MO in a unit of mol %, and wherein a point G represents a composition including 1 mol % of Li2O, 94 mol % of SiO2 and 5 mol % of MO, a point H represents a composition including 1 mol % of Li2O, 19 mol % of SiO2 and 80 mol % of MO, a point I represents a composition including 19 mol % of Li2O, 1 mol % of SiO2 and 80 mol % of MO, a point J represents a composition including 89 mol % of Li2O, 1 mol % of SiO2 and 10 mol % of MO, a point K represents a composition including 90 mol % of Li2O3, 9 mol % of SiO2 and 1 mol % of MO and a point L represents a composition including 5 mol % of Li2O, 94 mol % of SiO2 and 1 mol % of MO, a content of the composition Li2O—SiO2—MO ranging from 0.05 to 5.0 wt %.

6. The dielectric ceramic composition of claim 1, further comprising one or more oxides selected from the group consisting of oxides of Fe, Ni and Cu and wherein a total content of oxides of Fe, Ni, Cu, Mn, V and Cr is 0.04 to 1.0 mol %, the total content being calculated by assuming that the oxides of Fe, Ni, Cu, Mn, V and Cr are FeO, NiO, CuO, Mn2O3, V2O5 and Cr2O3, respectively.

7. A ceramic capacitor comprising one or more dielectric layers made of the dielectric ceramic composition of claim 1.

8. The ceramic capacitor of claim 7, wherein the glass component is composed of Li2O—BaO—TiO2—SiO2 and the content thereof ranges from 0.05 to 1.0 wt %.

9. The ceramic capacitor of claim 7, wherein the glass component is composed of B2O3—SiO2—MO, MO representing one or more oxides selected from the group consisting of BaO, SrO, CaO, MgO and ZnO, and wherein a composition of B2O3—SiO2—MO is within a range surrounded by 6 lines formed by cyclically connecting 6 points A, B, C, D, E and F in that order in a triangular composition diagram exhibiting compositional amounts of B2O3, SiO2 and Mo in a unit of mol %, and wherein a point A represents a composition including 1 mol % of B2O3, 80 mol % of SiO2 and 19 mol % of MO, a point B represents a composition including 1 mol % of B2O3, 39 mol % of SiO2 and 60 mol % of MO, a point C represents a composition including 29 mol % of B2O3, 1 mol % of SiO2 and 70 mol % of MO, a point D represents a composition including 90 mol % of B2O3, 1 mol % of SiO2 and 9 mol % of MO, a point E represents a composition including 90 mol % of B2O3, 9 mol % of SiO2 and 1 mol % of MO and a point F represents a composition including 19 mol % of B2O3, 80 mol % of SiO2 and 1 mol % of MO, a content of the composition B2O3—SiO2—MO ranging from 0.05 to 5.0 wt %.

10. The ceramic capacitor of claim 7, wherein the glass component is substantially composed of SiO2 and a content thereof is 0.20 to 4.0 mol %.

11. The ceramic capacitor of claim 7, wherein the glass component is composed of Li2O—SiO2—MO, MO representing one or more oxides selected from the group consisting of BaO, SrO, CaO, MgO and ZnO, and wherein the composition of Li2O—SiO2—MO is within a range surrounded by 6 lines formed by cyclically connecting 6 points G, H, I, J, K and L in that order in a triangular composition diagram showing compositional amounts of Li2O, SiO2 and MO in a unit of mol %, and wherein a point G represents a composition including 1 mol % of Li2O, 94 mol % of SiO2 and 5 mol % of MO, a point H represents a composition including 1 mol % of Li2O, 19 mol % of SiO2 and 80 mol % of MO, a point I represents a composition including 19 mol % of Li2O, 1 mol % of SiO2 and 80 mol % of MO, a point J represents a composition including 89 mol % of Li2O, 1 mol % of SiO2 and 10 mol % of MO, a point K represents a composition including 90 mol % of Li2O3, 9 mol % of SiO2 and 1 mol % of MO and a point L represents a composition including 5 mol % of Li2O, 94 mol % of SiO2 and 1 mol % of MO, a content of the composition Li2O—SiO2—MO ranging from 0.05 to 5.0 wt %.

12. The ceramic capacitor of claim 7, wherein the dielectric ceramic composition further comprises one or more oxides selected from the group consisting of oxides of Fe, Ni and Cu and wherein a total content of oxides of Fe, Ni, Cu, Mn, V and Cr is 0.04 to 1.0 mol %, the total content being calculated by assuming that the oxides of Fe, Ni, Cu, Mn, V and Cr are FeO, NiO, CuO, Mn2O3, V2O5 and Cr2O3, respectively.