MAGNETIC-ANISOTROPY OF RE TM FILMS MEASURED LOCALLY BY KERR TORQUE MAGNETOMETRY/

A Kerr torque magnetometer was developed for local investigation of th e magnetic anisotropy in the surface region. It gives directly the mag netization direction for external fields applied with different angles and magnitudes. Therefore it still works for anisotropy fields far la rger than the applied field and allows the evaluation of higher terms in the anisotropy energy. On Tb30Fe62Co8 films an enhanced anisotropy in the surface region was detected for increased film thickness. Agein g of samples with a surplus of nitrogen in the protective layer showed increasing inhomogenous anisotropy due to chemical reaction of Tb.