Degradation of the electric transport characteristics of the FeSe superconductor after a long-term storage

Abstract

The temperature dependence of the electrical resistance of an iron-containing superconductor with a nominal composition of FeSe0.94 was studied in the range of 4.2–300 K after a long storing for 7 years. This dependence was compared with a similar dependence of a freshly manufactured sample. After long-term storing, superconductivity was retained, but the temperature of the superconducting transition decreased significantly, and the structural phase transition characteristic of a freshly prepared sample is absent. The temperature dependences of the electrical resistance both for a freshly prepared sample and after a long storing are due to the scattering of electrons by phonons and defects, and can be described in terms of the Bloch–Gruneisen–Wilson model.