Temperature dependence of electrical transport properties of La4BaCu5−xCoxO13+δ conducting oxide thin films

Abstract

We fabricated Co-doped La4BaCu5O13+δ (La4BaCu5−xCoxO13+δ) epitaxial thin films with various amount of Co-substitution on SrTiO3 single-crystal substrates by a pulsed laser deposition method, and measured the resistivity from 10 to 1000 K. The resistivity below 700 K became large with increasing amount of Co-substitution, and that above 700 K was independent of Co-substitution. These measurement results suggested that the dominant component of carrier scattering changed from the impurity scattering of Co to phonon scattering at 700 K. As a result, the temperature dependence of the resistivity became weak systematically with increasing amount of Co-substitution. The resistivity measurement in N2-based 1% H2 clarified that the Co-substitution has no effect on the oxygen retention in the reduction atmosphere.