Dependence of physical properties, crystal structure and electric conductivity on substitution content and synthetic process of RE_2-xRE'_xCuO_4-δ(RE=La,Sm, RE'=Sm,Y) by using metal-organic decomposition.

Abstract

In our previous work, we synthesized T'-La_2-xRE_xCuO_4-δ (RE=Y,Lu,Sm,Eu) bulk samples, and investigated the relationship between physical properties, crystal structure and electric conductivity. In this work, we synthesized La_2-xRE_xCuO_4-δ (RE=Sm,Y) and Sm_2-xY_xCuO_4-δ film samples, and investigated effects of RE content and synthetic process on physical properties, crystal structure and electric conductivity. From XRD measurements, the main phase was T structure in La_2-xRE_xCuO_4-δ, and T'structure in Sm_2-xY_xCuO_4-δ although diffraction peaks of an impurity phase were observed depending on preparation condition. The samples showed the metallic resistivity behavior. Their resistivity remarkably decreased at low temperature, but they did not show zero resistivity.