Localization of Co–3d electrons in Y(Co 1− xAl x) 2 paramagnetic alloys with itinerant spin fluctuations

Abstract

Thermoelectric power ( S) and electrical resistivity ( ρ) of Y(Co 1− x Al x ) 2 alloys with x in the range of 0–0.15 have been measured at temperatures from 2 to 300 K, in the longitudinal magnetic field of 0–15 T. The present results show that there is a rapid variation of the transport properties and a peculiarity in the dependency of lattice parameter on x at x≈0.03; however, no change of the lattice symmetry has been detected. Although the precise mechanism of the anomaly at x≈0.03 has not been understood, the results suggest that it is related to a change in the localization of the Co–3d electrons caused by the increasing Co–Co separation and by the disorder within the Co-sublattice in the Y(Co 1− x Al x ) 2 alloys.