MAGNETIC-ANISOTROPY AND PHASE-TRANSITIONS IN CO-DOPED YTTRIUM-IRON-GARNET FILMS

YIG:Co,Ca,Ge films grown on (001) plane substrate were investigated do wn to liquid helium temperatures using torque anisometry technique. Su ccessively lowering temperature spin-reorientational transitions were observed between following easy magnetization axes (EMA) orientations: (i) at room temperature - four EMA inclined to the film plane from [1 11] directions; (ii) two EMA near the [110] and [1(1) over bar0$] dire ctions (iii) two other EMA near the [100] and [010] directions; (iv) o ne EMA near the [001] direction at the helium temperature.