Simultaneous observation of small- and large-energy-transfer electron-electron scattering in three-dimensional indium oxide thick films

Abstract

In three dimensional (3D) disordered metals, the electron-phonon (e-ph) scattering is the sole significant inelastic process. Thus the theoretical predication concerning the electron-electron (e-e) scattering rate 1/τϕ as a function of temperature T in 3D disordered metal has not been fully tested thus far, though it was proposed 40 years ago [A. Schmid, Z. Phys. 271, 251 (1974)]. We report here the simultaneous observation of small-and large-energy-transfer e-e scattering in 3D indium oxide thick films. In temperature region of T 100 K, the temperature dependence of resistivities curves of the films obey Bloch-Grüneisen law, indicating the films possess degenerate semiconductor characteristics in electrical transport property. In the low temperature regime, 1/τϕ as a function of T for each film can not be ascribed to e-ph scattering. To quantitatively describe the temperature behavior of 1/τϕ, both the 3D small-and large-energy-transfer e-e scattering processes should be considered (The small-and large-energy-transfer e-e scattering rates are proportional to T 3/2 and T 2 , respectively). In addition, the experimental prefactors of T 3/2 and T 2 are proportional to k −5/2 F ℓ −3/2 and E −1 F (kF is the Fermi wave number, ℓ is the electron elastic mean free path, and EF is the Fermi energy), respectively, which are completely consistent with the theoretical predications.Our experimental results fully demonstrate the validity of theoretical predications concerning both small-and large-energy-transfer e-e scattering rates.