GARNET POLYCRYSTALLINE FILM FOR OPTICAL MAGNETIC RECORDING MEDIUM, OPTICAL MAGNETIC RECORDING MEDIUM AND OPTICAL MAGNETIC RECORDING DISK

摘要

PURPOSE: To form a high-performance optical magnetic recording medium on an inexpensive substrate by stacking polycrystalline garnets by two or more layers at least, and besides, constituting the crystalline lattice constant between adjacent garnet layers so as to be different at a specified ratio or more. ;CONSTITUTION: This is a polycrystalline garnet represented by the composition of Bi_xR_3-x+uM_yFe_5+y+vO₁₂ (0≤x≤3, 0≤y≤5, -3≤u≤3, -5≤v≤5, R shows one or more kinds of rare earth elements including yttrium, and M a trivalent metal replaceable with iron). This is a garnet polycrystalline two-layer film for an optical magnetic recording medium, which consists of two layers whose crystal lattice constant is different by ±0.3% or more, and in which the average grain diameter of the garnet polycrystalline second layer made on the first layer is smaller than that of the first layer on a glass substrate, and besides is 1μm or under. Hereby, a polycrystalline garnet film consisting of fine crystal particles can be formed on an inexpensive substrate, and a high-performance polycrystalline optical magnetic recording medium can be obtained, using it.;COPYRIGHT: (C)1994,JPO