MAGNETIC PROPERTIES OF CALCIUM DOPED YIG

Recently a considerable attention has been given to the study of CaGe:YIG, Ca:YIG, CaGa:YIG epitaxial films in connection with the observed low temp,erature magnetization anomalies [I-41. These effects were ex- plained on the basis of the assumption that towards lower temperatures the hole is gradually localized and forms the tetrahedral ~e~+ (d) ion, which is ferromag- netically coupled to the octahedral ~e~+ (a) ioqs. (Ac- cording to the Goodenough-Kanamori rules we would rather expect the antiferromagnetic interaction.) The purpose of the present work is to bring further.infor- mation on the simple system Ca:YIG and to discuss possible explanations. Fig.