Magnetic Properties of Co/Pr Artificial Superlattice Thin Films Evaporated in O2 Atmosphere

Co/Pr artificial superlattice films were prepared by electron beam evaporation in O2 gas. The authors performed systematic investigations of the film magnetic properties, in particular (i) the dependence of the saturation magnetization Ms on temperature; (ii) the dependence of the perpendicular magnetic anisotropy constant K¿ on temperature; and (iii) the dependence of the polar Kerr rotation angle ¿k on wavelength. All the hysteresis loops of Co/Pr artificial superlattice films prepared in O2 gas were symmetric at 300 K, but a loop shift was observed for Co/Pr artificial superlattice films prepared in O2 gas at 1 × 10^¿5 Torr when films were cooled to 77 K in the presence of a magnetic field. The maximum loop shift was about 1.4 kOe. The dependence of ¿k on wavelength for Co/Pr deposited in O2 gas is different from that for Co. Polar Kerr rotations were large, and the maximum value of ¿k was - 0.77°.