Formation of Bi-substituted Garnet Films with Perpendicular Magnetization by Thermal Decomposition Method

Conditions for getting perpendicular magnetization were studied for Bi-substituted garnet films fabricated by pyrolysis with iron site substitution amount varied and the kind of rare earth ions varied. Torque measurements of Bi1.5Y1.5Fe5-xGaxO12 (x = 0, 0.4, 0.8, 1.2) showed that the film has magnetic easy axis perpendicular to the film plane when x = 0.8 and 1.2. It was also found that Ku results from the stress caused by the difference of thermal expansion coefficient between the film and the substrate.