Occurrence of Kondo-like behavior in electrical-conductivity of Al70Pd20+xMn10−x (x=0,1 and 2) icosahedral quasicrystals

Abstract

Abstract Zero-field and in-field (at 8 T) conductivity vs temperature (σ–T), magneto-resistance (Δρ/ρ), magnetization vs temperature (M–T) and magnetization vs field (M–H) of unannealed Al70Pd20Mn10 and annealed Al70Pd20Mn10, Al70Pd21Mn9 and Al70Pd22Mn8 quasicrystalline alloys have been studied in the temperature range of 1.4–300 K. Room temperature resistivity and the low-temperature magneto-resistance show a correlation with the corresponding magnetization. The σ–T for all the studied samples shows a pair of minima and maxima. The σ–T maxima show a correlation with the total magnetization. The analysis shows that σ–T is dominated by weak-localization effects. The minima are arising due to competing inelastic scattering times τi (e–ph scattering in the dirty metallic limit, τi ∝ T−2) and the Kondo-type spin-flip scattering time τsf whereas the maxima has been attributed to ‘Kondo-maxima’, occurring due to maxima in the spin-flip rate τ sf - 1 . The magneto-resistance of these samples shows a changeover from negative to positive where the negative component shows a correlation with the magnetization of the sample. The values of parameters derived from refinement give spin-flip scattering fields, which are found to be correlated with the total sample magnetization.