Magnetic properties of multilayered amorphous magnetic films

The magnetic properties of multilayered films consisting of an amorphous Gd-Co layer having a uniaxial magnetic anisotropy perpendicular to the film plane, and a Permalloy or a Tb-Fe layer having an in-plane anisotropy are studied. The thickness dependence of the shift of compensation temperature is studied in the amorphous Gd-Co film coated with Permalloy. When the Permalloy film is thicker than 600Å, the shift of compensation temperature becomes constant (about 5°C). Above a thickness of 2500Å of the amorphous Gd-Co film, the shift of compensation temperature becomes constant ( about 5°C). On the other hand, if the amorphous Gd-Co film is 1500Å thick, the change of compensation temperature does not occur. In the multilayered film having a nonmagnetic layer between the amorphous Gd-Co and the Permalloy film, no shift of compensation temperature occurs. The magnetic properties of thin Tb-Fe films coated on amorphous Gd-Co films have also been studied. When the thickness of the Tb-Fe is greater than about 100Å and thinner than about 500Å, the polarity of the Kerr hysteresis loops in double layered films changes.