METAL-INSULATOR-TRANSITION IN (LA1-XYX)NIO3

We are investigating the metal-insulator transition in (La1-xY(x))NiO3 . LaNiO3 is one of the very few oxides that exhibit metallic conductiv ity. It was reported that the substitution of Ln (Ln=Pr,Nd,Sm, and Eu) for La are seen metal-insulator transition in conductivity measuremen ts. This fact is expected that metal-insulator transition is caused by the substitution of Y for La, because Ni-O distance became long for Y 3+ is smaller than La3+. We prepared the sample of the partial substit ution of Y for La for the first time. In this study we found that a li ttle substitution of Y caused resistivity enlarge. It is expected that metal-insulator transition is caused by more substitution of Y.