MAGNETIC AND MAGNETO-OPTIC PROPERTIES OF AMORPHOUS GDFEBI-FILMS

Amorphous rare-earth-transition metal alloys of composition (Gd 1-xFex)1-yBiy with 0≤y≤0.17 have been prepared by high vaccum electron gun evaporation onto rotating glass substrates. The magnetic and magneto-optic properties have been investigated in the temperature range 4.2 K≤T≤TC. From the temperature dependence of the saturation magnetization the compensation temperature is found to decrease strongly with increasing y (Tcomp=0 for x=0.74, y=0.1) while the Curie temperature and the temperature for crystallization are much less affected. The magneto-optic Faraday and Kerr rotation display a considerable increase with increasing Bi-content. The temperature behavior can be interpreted in terms of the mean field analysis indicating a pronounced influence of the bismuth on the iron moment and the exchange constants.