Effect of plastic deformation on low-temperature specific heat and suprconductivity of Re

The low-temperature (4.2-50 K) heat capacity of plastically deformed single crystals of rhenium showing a positive shift in the critical temperature of the superconducting transition (sigmaTsub(c)/Tsub(c)sup(0) approximately 60%) was investigated. The plastic deformation increases the heat capacity; this increase can be characterized by the reduction of the characteristic temperature, which reaches 6% in strongly deformed specimens. The change in Tsub(c) under the effect of plastic deformation can be attributed to the renormalization of the parameter of the electron-background interaction lambda with the aid of the McMillan-Hoppfield relation lambda=const/M < THETA2 >, where < THETA2 > is the square of the mean phonon frequencies, and M is the atomic mass