MAGNETOOPTICAL OVERCOATING OF MNSB FILMS BY SURFACE OXIDATION

We demonstrate that surface oxidation has a pronounced effect on the m agnetooptical properties of MnSb films when used as a magnetooptical o vercoating technique. As a result of oxidation, the surface of the fil m was coated by an oxide layer and sharp divergent and dispersive stru ctures appeared in the Kerr rotation and ellipticity spectra at around 3.7 eV, respectively. The structures were very large and the absolute value of the Kerr ellipticity at 3.8 eV was more than 3 degrees, whic h is about 6 times larger than that of the MnSb film before oxidation. The change in these spectra due to surface oxidation was reproduced b y numerical calculations.