Effect of plastic deformation of V, Nb and Ta on superconducting trasition temperature and electron-positron annihilation spectra

Results of the combined studies on the positron annihilation and superconducting transition characteristics for V, Nb, and Ta are presented. Dependence of a critical temperature (Tsub(c)) on the degree of plastic deformation was measured. The correlation was found between the parameters of the positron annihilation and changes in Tsub(c) with deformation. On the basis of the electron-positron annihilation data a conclusion is made on a stronger influence of plastic deformation on Tsub(c) of those metals which exhibit a more essential electron charge redistribution in the vicinity of defects