RESISTIVITY MINIMUM IN NI76-XMN24PTX AND NI72-XMN28PTX AMORPHOUS-ALLOYS

The electrical resistivity rho as a function of temperature has been m easured for amorphous thin films of N76-xMn24Ptx (x = 0, 2, 5) and Ni7 2-xMn28Ptx(x = 0, 4, 10) alloys in the temperature range 1.5-400 K. Th e resistivity for every sample exhibits a low-temperature minimum, T-m in, following the logarithmic dependence. The results show the presenc e of two effects: one of them, associated with Kondo-like scattering, exists for all samples, the other, the electron-localized spin-wave sc attering mechanism is dominant for the samples with higher Mn concentr ations. In addition, the resistivity shows quadratic temperature behav iour in the intermediate temperature range. The examination of the qua dratic behaviours suggests that the scattering mechanism with magnetic origin is not negligible compared with that of the electron-structura l disordered scattering. Furthermore, the present data permits us for the first time to compare the nature of the resistivity minimum at low er temperatures for each sample of amorphous Ni(76-)xMn(24)Pt(x) and N i72-xMn28Ptx alloys with that of the corresponding alloys in the polyc rystalline phase.