Order-disorder and cold-work phenomena in CuPd alloys

Abstract

The copper-palladium system, in the composition range from 6 to 30 at. per cent palladium, has been studied. The order-disorder phenomena have been investigated and some disagreement with the work of Jones and Sykes observed. The effects of cold-work distortion on disordered and partially ordered samples were determined. When disordered CuPd alloys are cold-worked at room temperature, the electrical resistivity decreases, the magnetic susceptibility increases, the temperature coefficient of resistivity decreases and the thermoelectric power becomes increasingly negative. Similar effects are observed for partially ordered samples only after initial effects which are attributed to the destruction of order are completed. This produces an unusual marked maximum in the resistivity as a function of the degree of cold-work. It is suggested that the primary effects of cold-work are consistent with an electronic-structure change due to a shift in the relative centers of gravity of the s-p and d bands.