We present a comparison of electron-phonon interaction in NbB_2 and MgB_2, 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(\omega), (iii) Eliashberg function \alpha ^2F(\omega), and (iv) the solutions of the isotropic Eliashberg gap equation, clearly show significant differences in the electron-phonon interaction in NbB_2 and MgB_2. We find that the average electron-phonon coupling constant \lambda is equal to 0.59 for MgB_2 and 0.43 for NbB_2, leading to superconducting transition temperature T_c of around 22 K for MgB_2 and 3 K for NbB_2.
@article{arxiv.cond-mat/0210091,
title = {Electron-Phonon Interaction in NbB_2 : A Comparison with MgB_2},
author = {Prabhakar P. Singh},
journal= {arXiv preprint arXiv:cond-mat/0210091},
year = {2009}
}