Magneto-optical measurement of anisotropy energy constant(s) for amorphous rare earth, transition metal alloys

Optical investigation of magneto-optical films is complementary to conventional torque and VSM magnetometry. In our laboratory we are now measuring anisotropy energy constants of RE-TM thin films at temperatures from ambient to 150°C. An in-plane magnetic field (up to 16.5 KOe) is applied to a saturated sample with perpendicular magnetization. The movement of magnetization away from the perpendicular direction is monitored using the polar Kerr effect. At the HeNe wavelength of 632.8 nm, the Kerr effect is principally due to The top 500 angstroms of the transition metal subnetwork in the films.