Heat Treatment Effects in Amorphous Metals: Zr sub 70 Cu sub 30 and La sub 70 Cu sub 30

The electrical resistivity (4-300K), superconducting critical temperature and thermal conductivity (0.5-7K) of the amorphous metals Zr sub 70 Cu sub 3 sub 0 and La sub 70 Cu sub 30 were measured. Heat treatment below crystallization temperature induced changes in these properties. In particular, in the first stage of the annealing of Zr sub 7 sub 0 Cu sub 30 there are systematic changes in the thermal conductivity and the critical temperature, while the electrical resistivity remains constant. There is no simple correlation between the thermal conductivity processes in the low temperature and plateau regions. The thermal conductivity of as quenched La sub 70 Cu sub 30 is shown to be typical of amorphous metals, contrary to information previously reported. 11 ref.--BA.