Structural and magnetic disorder effects on electron transport properties of Cu-Ni films

Abstract

The resistivity and thermoelectric power of Cu_xNi_1-x films containing 0, 15, 20, and 25 at.% of Cu have been studied in the temperature range 300-675 K. The effect of postdeposition annealing on the microstructure and the transport properties of the alloy films deposited at 100 and 300 K have been studied in detail. The contributions to the resistivity of the alloy films of different compositions due to the structural, thermal, alloying, and magnetic disorder present in the films have been established. The thermoelectric power has been separated into two terms, one corresponding to the structural disorder and the other to the rest of the disorder effects. The presence of structural disorder has been shown to enhance the spin-disorder-induced effects on electron transport properties. The observed concentration and temperature dependence of the transport properties and their anomalous behavior at the Curie temperature can be understood in terms of the thermal and structure-induced spin-disorder scattering in the alloy films.