SURFACE AND INTERFACE MAGNETISM BY MOSSBAUER SPECTROSCOPY

Rbsum6.- Le comportement magngtique d'un cristal ordonnb magngtiquement, prSs d'une surface ou d'un interface est un ph6nomSne trls intbressant. Le moment magnbtique local d'un atome superfi-ciel, l'influence de la temperature sur l'aimantation de surface et l'anisotropie superficielle ont &ti5 6tudibs par effet MEssbauer du 57~e. Les rbsultats obtenus par d'autres mdthodes sont analysbs brilvement. Les avantages et les limites de la spectrombtrie ~Essbauer pour l'btude des surfaces sont discutss. Abstract.- Magnetic behaviors near a surface, or an interface, of a magnetically ordered crystal are of great interest. Local magnetic moment of a surface atom, temperature dependence of surface magnetization and surface anisotropy are studied from ''~e Msssbauer measurements. The results obtained by complementary means arebrieflyreviewed. The advantages and also limits of the MESS-bauer spectroscopy as a tool for surface magnetic studies are discussed. 1. Problems in surface magnetism.- In recent years magnetic properties of transition metal surfaces have been of great interest from a viewpoint of fun-damental physics and also in connection with surfa