Electronic properties of Ca1-xAlxmetallic glasses

Abstract

The electronic properties have been studied of four Ca_1-xAl_x metallic glasses (x=0.25, 0.30, 0.35 and 0.40) prepared by liquid quenching. The measurements involved are the electrical resistivity in the range 2-700K, the Hall coefficient at 77-300K, the low-temperature specific heat at 1.5-6K and the magnetic susceptibility at 77-600K. All experimental data indicate a nonfree-electron behaviour. The effective electron concentration and the Fermi momentum are deduced from the Hall coefficient and found to be far below the free-electron values. Both the electronic specific heat coefficient and the magnetic susceptibility decrease with increasing Al content. The relatively large paramagnetism suggests the presence of d-character states at the Fermi level. The electrical resistivity is empirically found to obey the relation rho = rho ₀-BT^1.2(B>0) below 120K and to be proportional to temperature with a negative TCR in the range 120-400K.