PURPOSE: To increase the polar Kerr rotating angle and Faraday rotating angle in the stage of reproduction and to obtain an S/N ratio suitable substantially to practicable use by forming an amorphous film consisting of garnet compd. on both sides of a vertically magnetized film by a sputtering method or vapor deposition method.
CONSTITUTION: An amorphous film 2 consisting of a garnet compd. is formed by sputtering or vapor deposition above a base plate 1 consisting of transparent glass of synthetic high polymer resin, etc. and a vertical magnetized film 3 consisting of a magnetic metallic film is formed by a sputtering method of vapor deposition method of the film surface over the film 2; further an amorphous film 2 consisting of a garnet compd. and a metallic reflecting film 4 are formed in this order over the same by the similar method. An amorphous film (0.1μm thickness) consisting of a garnet compd. is formed by a sputtering method with a sintered body (100mm) of a Y3 Fe5O12 as a target on, for example, a glass base plate (0.3mm thickness) and multilayered films consisting of an amorphous Fe75 Tb25 film (0.02μm thickness) as a vertically magnetized film and a thin Al film (0.1μm thickness) as a metallic reflecting films are formed thereon by the similar method.
SUGITA KEN
NIIHARA TOSHIO
KANEKO KATSUHIRO
ANDOU KEIKICHI
