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:
Jul. 11, 2000
Filed:
May. 04, 1998
TDK Corporation, Tokyo, JP;
Abstract
A magneto-optical recording medium capable of direct overwriting in a light intensity modulation mode comprises a magnetic multilayer structure comprising, in order form an surface side thereof, a readout layer R.sub.01, a memory layer M.sub.1, an exchange force control layer C.sub.12 and a recording layer W.sub.2, four layers in all. The magnetic multilayer structure satisfies TC.sub.W2 >Tc.sub.M1, t.sub.R01 /(t.sub.R01 +t.sub.M1)=0.3 to 0.6, and t.sub.R01 +t.sub.M1 =20 to 40 nm where Tc.sub.M1 is a Curie temperature of M.sub.1, Tc.sub.W2 is a Curie temperature of W.sub.2, t.sub.R01 is a thickness of R.sub.01, and t.sub.M1 is a thickness of M.sub.1. R.sub.01 contains Gd, Fe, and Co as main components with the proviso that Gd is contained in an amount of 23 to 27 at %, M.sub.1 contains Tb, Fe, and Co as main components with the proviso that Tb is contained in an amount of 21 to 25 at %, and C.sub.12 contains Gd, Fe, and Co as main components with the proviso that Gd is contained in an amount of 23 to 32 at %, and has a thickness of 30 nm or below.