Dependence of physical properties, crystal structure and electric conductivity on substitution content and synthetic process of T'-La_2-xRE_xCuO_4-δ(RE=Sm, Y)

Abstract

We synthesized La_2-xRE_xCuO_4-δ(RE=Sm, Y) bulk samples and thin film samples. Then, we investigated the relationship between physical properties, crystal structure and electric conductivity by changing Sm, Y content and synthetic process. The main phase kept T'structure, although T structure and precursor were observed as a sub-phase depending on preparation condition. When the resistivity showed the metallic behavior, the resistivity remarkably decreased at low temperature area, but they did not show zero resistivity. In addition, we analyzed the crystal structure by the Rietveld method from synchrotron X-ray diffraction, and investigated the relation among the oxygen deficiency, the site, and the electric conductivity.