Pressure effect on the superconducting and the normal state of ss-Bi2Pd

Article

关键词: ELECTRICAL-RESISTIVITY;   

DOI  :  10.1103/PhysRevB.97.134505

来源: SCIE

【 摘 要 】

The pressure effect up to 24.0 kbar on superconducting and normal-state properties of ss-Bi2Pd single crystal (T-c approximate to 4.98 K at ambient pressure) has been investigated by measurements of the electrical resistivity. In addition, we have performed the heat capacity measurements in the temperature range 0.7-300 K at ambient pressure. The recent calculations of electronic density of states, electron-phonon interaction spectral function, and phonon density of states of ss-Bi2Pd [ Zheng and Margine, Phys. Rev. B 95, 014512 (2017)], are used to fit the resistivity and the heat capacity data. In the superconducting state we have focused on the influence of pressure on the superconducting transition temperature T-c and upper critical field H-c2 and a negative effect with dT(c)/dp = -0.025K/kbar and dH(c2)/dp = -8mT/kbar is found. A simplified Bloch-Gruneisen model was used to analyze the pressure effect on the temperature dependence of the normal-state resistivity. The obtained results point to a decrease of the electron-phonon coupling parameter lambda and to a shift of phonon frequencies to higher values with pressure. Moreover, the temperature dependence of the normal-state resistivity follows a T-2 dependence above T-c up to about 25 K. Together with the enhanced value of Sommerfeld coefficient gamma = 13.23 mJ mol(-1) K-2 these results point to a certain role of the electron-electron interaction in the superconducting pairing mechanism in ss-Bi2Pd.

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