Interplay of the Boltzmann-type ordinary transport and quantum corrections in Ag-Cu-Ge amorphous alloy system. I. Temperature dependence of electrical resistivity

The electrical resistivity has been measured in the temperature range 2-300 K for (Ag_0.5Cu_0.5)_1-xGe_x amorphous alloys over a wide composition range 0<or=x<or=0.95. The scattering mechanism is analysed in the metallic regime, which is assumed to persist up to 60 at.% Ge alloy or the resistivity below approximately 1000 mu Omega cm. In the low-resistivity regime below about 200 mu Omega cm, the rho -T characteristics can be consistently explained in terms of the ordinary scattering mechanism based on the Boltzmann equation or the generalised Faber-Ziman theory. In the high-resistivity regime above 200 mu Omega cm, the quantum corrections are shown to play a significant role: the rho -T characteristics below 15 K and above about 30 K are essentially caused by the electron-electron and the electron-phonon interaction respectively. The dominant role of quantum corrections has been also confirmed by studying the effect of the dimensionality on the rho -T characteristics.