Electronic structure and electron-phonon interaction in YAl2Si2

Abstract

We calculate the electronic structure, phonon spectrum and electron-phonon (EP) interaction for YAl2Si2 using the full-potential, density-functional-based method. The Y 4d-like band crosses the Fermi level. The main contribution to the density of states (DOS) at the Fermi level comes from Y 4d-states. Our results for the phonon DOS and the Eliashberg spectral function show that in-plane bond-stretching modes have high frequency and couple more strongly to the electrons. Both the calculated EP coupling constant λ (0.31) and the estimated superconducting transition temperature TC (0.15 K with μ* ∼ 0.15) are very low in YAl2Si2. The differences of electronic structure, phonon structure and transport behavior between YAl2Si2 and CaAl2Si2 are discussed. © 2006 Elsevier B.V. All rights reserved.