Claims
- 1. A luminescent material having a hexagonal crystal structure corresponding to .beta.-alumina, .beta."-alumina, or the hexagonal ferrites, said luminescent material being activated by cerium and terbium, and having a non-stoichiometric composition comprising a compound of the formula
- Ce.sub.x Tb.sub.y MgAl.sub.11 O.sub.19
- wherein
- 0.60.ltoreq.x.ltoreq.0.80
- 0.20.ltoreq.y.ltoreq.0.40
- x+y=1
- and wherein excess Al.sub.2 O.sub.3 is in the luminescent material up to 10 mol.%.
- 2. A luminescent material of claim 1, wherein a compound of the formula Ce.sub.0.70 Tb.sub.0.30 MgAl.sub.11 O.sub.19 is present.
- 3. A low-pressure mercury vapor discharge lamp provided with the luminescent material of claim 1.
Priority Claims (1)
Number |
Date |
Country |
Kind |
7214862 |
Nov 1972 |
NLX |
|
Parent Case Info
This is a continuation of application Ser. No. 585,969, filed Mar. 5, 1984, now abandoned which is a division of application Ser. No. 450,488, filed 12/16/82 said application Ser. No. 450,488 being a division of application Ser. No. 144,731, filed Apr. 28, 1980, now U.S. Pat. No. 4,382,207 which is a division of application Ser. No. 876,826 filed Feb. 10, 1978, now U.S. Pat. No. 4,216,408, which is a continuation of application Ser. No. 699,344 filed June 24, 1976, now abandoned, which is a continuation of application Ser. No. 410,104, filed Oct. 26, 1973, now abandoned.
US Referenced Citations (1)
Number |
Name |
Date |
Kind |
4382207 |
Verstegen et al. |
May 1983 |
|
Divisions (3)
|
Number |
Date |
Country |
Parent |
450488 |
Dec 1982 |
|
Parent |
144731 |
Apr 1980 |
|
Parent |
876826 |
Feb 1978 |
|
Continuations (3)
|
Number |
Date |
Country |
Parent |
585969 |
Mar 1984 |
|
Parent |
699344 |
Jun 1976 |
|
Parent |
410104 |
Oct 1973 |
|