Lattice dynamics and electron-phonon coupling in transition-metal diborides

The phonon density of states of transition metal diborides TB2 with T=Ti, V, Ta, Nb, and Y has been measured using the technique of inelastic neutron scattering. The experimental data are compared with ab initio density-functional calculations whereby an excellent agreement is registered. The calculations thus can be used to obtain electron-phonon spectral functions within the isotropic limit. A comparison with similar data for MgB2 and AlB2, which were subject of prior publications as well as parameters important for the superconducting properties are part of the discussion.