Resistivity minimum in Ni76−Mn24Pt and Ni72−Mn28Pt amorphous alloys

Abstract

Abstract The electrical resistivity ϱ as a function of temperature has been measured for amorphous thin films of Ni 76 − x Mn 24 P x ( x = 0, 2, 5) and Ni 72 − x Mn 28 Pt x ( x = 0, 4, 10) alloys in the temperature range 1.5–400 K. The resistivity for every sample exhibits a low-temperature minimum, T min , following the logarithmic dependence. The results show the presence of two effects: one of them, associated with Kondo-like scattering, exists for all samples, the other, the electron-localized spin-wave scattering mechanism is dominant for the samples with higher Mn concentrations. In addition, the resistivity shows quadratic temperature behaviour in the intermediate temperature range. The examination of the quadratic behaviours suggests that the scattering mechanism with magnetic origin is not negligible compared with that of the electron-structural disordered scattering. Furthermore, the present data permits us for the first time to compare the nature of the resistivity minimum at lower temperatures for each sample of amorphous Ni 76 − x Mn 24 P x and Ni 72 − x Mn 28 Pt x alloys with that of the corresponding alloys in the polycrystalline phase.