Stock material or miscellaneous articles – Composite – Of inorganic material
Patent
1988-09-29
1991-12-31
Thibodeau, Paul J.
Stock material or miscellaneous articles
Composite
Of inorganic material
428900, 252 6259, G11B 2300
Patent
active
050771469
ABSTRACT:
Disclosed is a magnetic powder for high-density magnetic recording, formed of a substituted hexagonal ferrite possessing an average particle diameter in the range of 0.01 to 0.2 .mu.m and a coercivity in the range of 200 to 2,000 Oe and characterized by the fact that the substituted hexagonal ferrite has at least 0.05 to 0.5 atom of at least one element selected from the group consisting of Zr and Hf per chemical formula and at least one element selected from among the elements other than Zr and Hf substituted for part of the Fe atom of the ferrite, and a magnetic recording medium of the present invention comprises a substrate and the magnetic powder mentioned above deposited on the substrate. Since the magnetic powder comprises very minute particles, the magnetic powder and the magnetic recording medium are capable of high-density recording. The magnetic powder has an improved desirably controlled aspect ratio for orientation and the temperature characteristic of coercivity (Hc) as compared with the countertype formed of a hexagonal ferrite which has neither Zr nor Hf substituted for the Fe atom.
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Ido Tadashi
Kubo Osamu
Nomura Tutomu
Yokoyama Hirotaka
Kabushiki Kaisha Toshiba
Resan Stevan A.
Thibodeau Paul J.
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