Superconductivity,magnetic susceptibility and thermal relaxation in amorphous CuZr

From measurements of the superconducting transition temperature and valence magnetic susceptibility ξ_v, of amorphous Cu_100?xZr_x (30? x ? 80), we find that ln T_c varies as (ξ_v)^?1 implying that with changing x, T_c is controlled only by the electronic density of states. By contrast, thermal relaxation reduces T_c substantially, leaving ξ_v almost unaltered, implying that T_c is changed only by change in the effective electron-electron coupling.