magnetically ordered materials;
electronic transport;
exchange and superexchange;
D O I:
10.1016/0038-1098(95)00843-8
中图分类号:
O469 [凝聚态物理学];
学科分类号:
070205 ;
摘要:
The effects of isovalent substitution into the lanthanide sites on the magnetoresistance of La0.67-xYxCa0.33MnO3-delta oxides are presented. We will provide evidence that a key signature of the magnetic properties of these oxides is the presence of an unusual long tail in the magnetization vs temperature curves M(T), extending well above the Curie temperature and which is very sensitive to the applied magnetic field and becomes increasingly important with the concentration Of Y in the lattice. These features signal a strong polarizability of the spin clouds in these materials as our Mossbauer experiments will clearly demonstrate.