Garnet polycrystalline film for magneto-optical recording medium
AssigneesNippon Steel Corporation, Nippon Hoso Kyokai
InventorsKenji Shimokawa, Norikazu Kawamura
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Abstract
A garnet polycrystalline film for a magneto-optical recording medium including at least two layers of polycrystalline garnet represented by Bi.sub.x R.sub.3-x M.sub.Y Fe.sub.5-Y O.sub.12, where 0.ltoreq.X.ltoreq.3, 0 Y.ltoreq.5, R represents one or more rare earth elements containing yttrium, and M represents Ga, Al or In, wherein crystal lattice constants of these adjacent two layers are different from each other by .+-.0.3% or more, and an average crystal grain diameter of one of the layers is smaller than that of the other layer and 1 .mu.m or less, and a magneto-optical recording disk using this garnet polycrystalline film.
Claims14
A garnet polycrystalline film for a magneto-optical recording medium comprising:
- two layers of polycrystalline garnet represented by Bi.sub.X R.sub.3-X M.sub.Y Fe.sub.5-Y O.sub.12 where 0.ltoreq.X.ltoreq.3, 0.ltoreq.Y.ltoreq.5, R represents one or more rare earth elements including yttrium, and M represents Ga, Al or In);
- wherein:
- said two layers being adjacent to each other and having crystal lattice constants different by .+-.0.3% or more, and an average crystal grain diameter of one of the layers being smaller than that of the other layer and 1 .mu.m or less.
A magneto-optical recording disk comprising:
- a substrate;
- and
- a garnet polycrystalline film formed on said substrate;
- wherein:
- said garnet film includes two layers of polycrystalline garnet represented by Bi.sub.X R.sub.3-X M.sub.Y Fe.sub.5-Y O.sub.12 where 0.ltoreq.X.ltoreq.3, 0.ltoreq.Y.ltoreq.5, R represents one or more rare earth elements including yttrium, and M represents Ga, Al or In) said two layers being adjacent to each other and having crystal lattice constants different from each other by .+-.0.3% or more;
- and
- an average crystal grain diameter of one of the layers being smaller than that of the other layer and 1 .mu.m or less.
Dependencies are inferred from the claim text.