Electron-electron scattering in tungsten

Abstract

A new radio-frequency size-effect study in tungsten of the temperature dependence of the electron scattering rate, v, below 9K, shows that using v= alpha T2+ beta T3, alpha is essentially isotropic, insensitive to impurity concentration and thickness independent. The experimental value of alpha is the same on the electron jack and on the hole octahedron, at 0.6*197 s-2, and is slightly higher, 1.1*107 s-1K-2, on the ball of the Fermi surface, in good agreement with electron-electron scattering calculations by Potter and Morgan (1979). This scattering rate corresponds to a contribution, AT2, to the electrical resistivity, with A approximately=7 f Omega mK-2, which is close to the lowest values obtained from resistivity measurements. It is shown that the strong size dependence of A, as recently observed by Startsev and Cherepanov, can be explained by the Soffer model for specularly reflecting surfaces, when electron-electron scattering is dominant in the bulk.