Direct determination of Debye temperature and electron-phonon interaction in 1T-VSe2 -: art. no. 073107

Crystals of the layered two-dimensional transition-metal dichalcogenide 1 T-VSe2 are investigated by point-contact spectroscopy in the charge-density wave state. Relevant characteristics such as mean, root-mean-square, and Debye phonon frequencies are obtained. The Debye temperature is Theta (D) = 220 +/- 5 K, close to that of 2H-NbSe2. The point-contact function g(pc)(omega) of the electron-phonon interaction reveals a moderate coupling constant lambda (pc) = 0.27. Consequently, the Coulomb potential, the density of states at the Fermi level, and the deformation potential are estimated to be of order 0.22 eV, 2.5 states/eV, and 0.22 eV/Angstrom, respectively.