Grain boundary-free crystalline body of manganese-based composite oxide and method for the preparation thereof

摘要

A grain boundary-free crystalline body of a perovskite structure having a chemical composition of the formula Pr1-xMxMnO3, in which M is calcium or strontium and the subscript x is a number of 0.3 to 0.5, exhibits magnetoresistance behavior with a phase transition between an insulator phase and a ferromagnetic metallic phase accompanied by the phenomenon of hysteresis. The grain boundary-free crystalline body can be obtained by subjecting a sintered body of a powder blend comprising the oxides of praseodymium, manganese and calcium or strontium to a crystal growing treatment by the floating zone-melting method in an atmosphere of oxygen.