Electron-Phonon Interaction in NbB₂ : A Comparison with MgB₂

2002/10/04 by Prabhakar P. Singh · 3 citations
Materials Science · Physics and Astronomy · #Boron and Carbon Nanomaterials Research #Physics of Superconductivity and Magnetism #Superconductivity in MgB2 and Alloys #cond-mat.supr-con

paper · pdf · doi:10.1016/s0038-1098(02)00819-0

published as Solid State Commun. 125/126, 323-326 (2003)

arxiv created 2002/10/04 · arxiv updated 2009/11/30

Abstract

We present a comparison of electron-phonon interaction in NbB₂ and MgB₂, calculated using full-potential, density-functional-based methods in P6/mmm crystal structure. Our results, described in terms of (i) electronic structure, (ii) phonon density of states F(ω), (iii) Eliashberg function α²F(ω), and (iv) the solutions of the isotropic Eliashberg gap equation, clearly show significant differences in the electron-phonon interaction in NbB₂ and MgB₂. We find that the average electron-phonon coupling constant λis equal to 0.59 for MgB₂ and 0.43 for NbB₂, leading to superconducting transition temperature T_c of around 22 K for MgB₂ and 3 K for NbB₂.

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