MAGNETOOPTICAL PROPERTIES OF PR,NI-SUBSTITUTED AND CE,NI-SUBSTITUTED YIG EPITAXIAL-FILMS PREPARED BY SPUTTERING

Films of Y2Rl(Fe, Ni)(5)O-12 (R=Pr, Ce) have been epitaxially grown in situ on Gd3Ga5O12 (111) substrates by rf sputtering. Faraday rotation of Ce, Ni:YIG film decreased with valence change of Ce ions from 3+ t o 4+ induced by Ni substitution. On the other hand, Pr, Ni:YIG films s howed negative Faraday rotation in the visible which slightly increase s in negative sign for Ni substitution. Magneto-optical spectrum measu rement in a photon energy range extended to 4.2 eV indicated that the negative Faraday rotation in the visible is dominantly ascribed to a p aramagnetic dispersion at 3.1 eV and the rotation increased by Ni subs titution may be caused by spectral structure observed above 3.5 eV, as sociated with pr(4+).