Magnetic-optical recording medium
US5418076A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 20, 1991 |
| Grant date | May 23, 1995 |
| Priority date | — |
| Expiry date | Nov 20, 2011 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S428/90
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A magneto-optical recording medium in which n layers (n is an odd number equal to or more than 5) of magnetic thin film are exchange-coupled to be laminated on a substrate, and assuming that the n layers of magnetic thin film are the first magnetic layer, the second magnetic layer, . . . the n-th magnetic layer in sequence, and the Curie temperature on the i-th magnetic layer is Tc.sub.i, the following conditions are satisfied (where Tc.sub.n+1 is an ambient temperature and m is an arbitrary natural number equal to or less than (n-1)/2). (1) Tc.sub.2m+1 .gtoreq.Tc.sub.2m, Tc.sub.1 .gtoreq.Tc.sub.2m (2) Tc.sub.2m .gtoreq.Tc.sub.2(m+1) (3) In a cooling process after heating the medium to a temperature of Tc.sub.2 or more, when the temperature of the (2m)-th magnetic layer drops down to a temperature near Tc.sub.2m, the magnetization of the (2m)-th and (2m+1)-th magnetic layers orients to the (2m-1)-th magnetic layer so that the bonding state due to exchange interaction may be stable, while the magnetization on the (2m-1)-th magnetic layer retains its immediately previous orientation state.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.