Some anomalous aspects of resistivity behavior in dilute chromium alloy systems

Abstract

The addition of up to 0.3 at. % Mn to pure Cr leads to a fall in ρ at low temperatures resulting in a crossover of the ρ(T) curves of the alloys vís-à-vís that of pure Cr. The effect of vanadium impurities (0.1, 0.2, and 0.3 at. %) on the binary matrix Cr+0.5 at. % Ir is, however, different in nature in that there is a common crossover point (≊280 K) below which the resistivity of V-containing alloys is higher, and above which it is lower, than that of the host, and the magnitude of the effect increases with the rise in V content. Yet another type of anomalous behavior is observed for CrPd alloys where the overall resistivity curve rises with increase in Pd content from zero to 0.8 at. % but the ρ(T) curves register a monotonic fall with further rise in Pd content. All these complex features of resistivity are discussed in relation to the spin density wave (SDW) antiferromagnetism of chromium as influenced by the effects of impurity scattering, change in e/a ratio, and the possibility of local moment formation on impurity atoms.