Claims
- 1. A magnetic recording powder for use as a material for magnetic recording media including magnetic tapes and magnetic cards, said powder having a high coercive force at room temperatures and a low Curie point, consisting of:
- at least one element selected from the group consisting of Y and rare-earth elements (R): 5-20 atomic %;
- B: 5-20 atomic %;
- Mn: 4-20 atomic %; and
- Fe and inevitable impurities: the balance, said powder having a means particle size of 0.5-2 .mu.m and a mean crystal grain size of 0.1-0.4 .mu.m.
- 2. The magnetic recording powder as claimed in claim 1, wherein R: 10-15 atomic %, B: 5-10 atomic %, and Mn: 4-12 atomic %.
- 3. A magnetic recording powder for use as a material for magnetic recording media including magnetic tapes and magnetic cards, said powder having a high coercive force at room temperatures and a low Curie point, consisting of:
- at least one element selected from the group consisting of Y and rare-earth elements (R): 5-20 atomic %;
- B: 5-20 atomic %;
- Mn: 4-20 atomic %;
- Al: 1-10 atomic %; and
- Fe and inevitable impurities: the balance, said powder having a mean particle size of 0.5-2 .mu.m and a mean crystal grain size of 0.1-0.4 .mu.m.
- 4. The magnetic recording powder as claimed in claim 3, wherein R: 10-15 atomic %, B: 5-10 atomic %, Mn: 4-12 atomic %, and Al: 3-10 atomic %.
- 5. A magnetic recording powder for use as a material for magnetic recording media including magnetic tapes and magnetic cards, said powder having a high coercive force at room temperatures and a low Curie point, consisting of:
- at least one element selected from the group consisting of Y and rare-earth elements (R): 5-20 atomic %;
- B: 5-20 atomic %;
- Mn: 4-20 atomic %;
- Cr: 1-10 atomic %; and
- Fe and inevitable impurities: the balance, said powder having a mean particle size of 0.5-2 .mu.m and a mean crystal grain size of 0.1-0.4 .mu.m.
- 6. The magnetic recording powder as claimed in claim 5, wherein R: 10-15 atomic %, B: 5-10 atomic %, Mn. 4-12 atomic %, and Cr: 3-10 atomic 9.
- 7. A magnetic recording powder for use as a material for magnetic recording media including magnetic tapes and magnetic cards, said powder having a high coercive force at room temperature and a low Curie point, consisting of:
- at least one element selected from the group consisting of Y and rare-earth elements (R): 5-20 atomic %;
- B: 5-20 atomic %;
- Mn: 4-20 atomic %;
- Al: 1-10 atomic %;
- Cr: 1-10 atomic %: and
- Fe and inevitable impurities: the balance, said powder having a mean particle size of 0.5-2 .mu.m and a mean crystal grain size of 0.1-0.4 .mu.m.
- 8. The magnetic recording powder as claimed in claim 7, wherein R: 10-15 atomic %, B: 5-10 atomic %, Mn: 4-12 atomic %, Al: 3-10 atomic %, and Cr: 3-10 atomic %.
- 9. The magnetic recording powder as claimed in any of claims 1-8, wherein said powder has a mean particle size of 0.7-1.5 .mu.m and a means crystal grain size of 0.1-0.4 .mu.m.
- 10. The magnetic recording powder as claimed in any of claims 1-8, wherein said powder has a mean particle size of 0.5-2 .mu.m and a mean crystal grain size of 0.2-0.4 .mu.m.
- 11. The magnetic recording powder as claimed in any of claims 1-8, wherein said powder has a mean particle size of 0.7-1.5 .mu.m and a mean crystal grain size of 0.2-0.4 .mu.m.
- 12. The magnetic recording powder as claimed in claim 7, wherein the total amount of Mn, Al, and Cr satisfies a condition of 5 atomic %.ltoreq.Mn+Al+Cr.ltoreq.20 atomic %.
- 13. The magnetic recording powder as claimed in any of claim 2, 4, 6 or 8, wherein the rare-earth elements comprise Nd.
- 14. The magnetic recording powder as claimed in claim 2, 4, 6, or 8, wherein the rare-earth elements comprise Nd and Dy.
Priority Claims (1)
Number |
Date |
Country |
Kind |
2-72840 |
Mar 1990 |
JPX |
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Parent Case Info
This application is a continuation-in-part application of application Ser. No. 07/671,260 filed Mar. 18, 1991 now abandoned.
US Referenced Citations (4)
Number |
Name |
Date |
Kind |
4792368 |
Sagawa et al. |
Dec 1988 |
|
4802931 |
Croat |
Feb 1989 |
|
4975130 |
Matsuura et al. |
Dec 1990 |
|
5015307 |
Shimotomai et al. |
May 1991 |
|
Foreign Referenced Citations (4)
Number |
Date |
Country |
59-229461 |
Dec 1984 |
JPX |
60-144909 |
Jul 1985 |
JPX |
61-51901 |
Mar 1986 |
JPX |
61-119651 |
Jun 1986 |
JPX |
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
671260 |
Mar 1991 |
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