Magnetoresistance studies in Al70Pd20+xMn10−x (x=0, 1) icosahedral quasicrystals

Zero-field and in-field (at 8 T) conductivity vs. temperature (σ–T) and magnetoresistance (Δρ/ρ) of as-prepared and unannealed Al70Pd20Mn10, annealed Al70Pd20Mn10, and annealed Al70Pd21Mn9 quasicrystalline (qc) alloys have been studied in the temperature range of 1.4–300 K. From room temperature to 30 K, σ–T appears to be dominated by weak-localization effects including electron–phonon (e–ph) scattering as the inelastic process. σ–T minima are possibly due to the dephasing arising from temperature dependent spin–spin scattering, resulting from a cluster-glass-like transition as indicated by the χ–T and M–H measurements. The σ–T maxima at ∼9 K and the negative Δρ/ρ at 1.4 K originate probably from some ferromagnetic type magnetic interaction in the sample, which quenches the spin–spin scattering effects.