Effect of Ge4+ ion on electrical properties of (La0.1Ca0.9)(Mn1-xGex)O-3

摘要

Orthorhombic perovskite-type (La0.1Ca0.9)(Mn1-xGex) O-3 was synthesized in the range (0.00 less than or equal to x less than or equal to 0.10). Since the ionic radius of the Ge4+ ion is equal to that of the Mn4+ ion, the (Mn, Ge)O(1, 2) distances and the angles for (Mn, Ge)-O(1, 2)-(Mn, Gel are independent of the composition (x). From the measurement of the electrical resistivity (rho), ail manganates exhibit a metal-insulator transition. With increasing x, the metal-insulator transition temperature (T-t) increases and d rho/dT decreases. The cation-anion-cation overlap integrals are weakened by the Ge4+ ion. (C) 1998 Academic Press. [References: 10]