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Theoretical Study of Electronic Structure and Superconductivity in Nb_(1-x)B_2 Alloys

P. Jiji Thomas Joseph·Prabhakar P. Singh
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Abstract

Using the Korringa-Kohn-Rostoker coherent-potential approximation in the atomic-sphere approximation (KKR-ASA CPA) we have studied the changes in the electronic structure and the superconducting transition temperature T_{c} in Nb_{1-x}B_{2} alloys as a function of x. We find that the variation in the electronic structure of Nb_{1-x}B_{2} alloys as a function of x is consistent with the rigid-band model. However, the variation of T_{c}, obtained using the Allen-Dynes equation within the Gaspari-Gyorffy formalism to estimate the electron-phonon matrix elements, does not follow the expected trend. We associate this disagreement to the use of a constant ω_{rms} in the Allen-Dynes equation over the whole range of vacancy concentration, thereby indicating the importance of lattice dynamical effects in these systems.

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P. Jiji Thomas Joseph, Prabhakar P. Singh. 2003-04-18. Theoretical Study of Electronic Structure and Superconductivity in Nb_(1-x)B_2 Alloys. https://doi.org/10.1016/s0921-4534(03)01091-8

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