The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 20, 1998
Filed:
Mar. 08, 1996
Kaoru Masuda, Yasugi, JP;
Hitachi Metals, Ltd., Tokyo, JP;
Abstract
The invention provides a magneto-optical recording medium target and a manufacture method thereof which target can produce the leakage magnetic flux in sufficient density and has the high mechanical strength. The target is a sintered body containing 15 to 30 atomic % at least one rare earth metal and the balance at least one transition metal, in which alloy powder having such a composition is sintered so that the original morphology of the alloy powder essentially remains. Specifically, the target has a micro structure in which the alloy powder particles consisted of the rare earth metal and the transition metal are interconnected through grain boundary phases. The target is able to have the deflective strength not less than 50 MPa, the relative density not less than 99%, and the content of oxygen not more than 1000 ppm. Particulate micro structures preferably have a grain size d.ltoreq.250 .mu.m and a volume mean size d.sub.av of 50.ltoreq.d.sub.ad .ltoreq.120 .mu.m. The target can be manufactured by producing alloy powder having the above target composition and sintering the alloy powder at a temperature lower than the liquid phase occurring temperature by 30.degree. C. or more and under a high pressure not less than 90 MPa.