Hall-effect and resistivity study of the heavy-fermion systemURu2Si2

Abstract

Hall-effect measurements from 2–300 K and resistivity measurements up to 1200 K are presented for different orientations of ${\mathrm{URu}}_2$ ${\mathrm{Si}}_2$ single crystals. For H∥c a decomposition into an ordinary and an extraordinary Hall effect allows an estimate of the temperature dependence of the carrier concentration and provides evidence for the existence of a reconstruction of the Fermi surface at 17 K and the onset of coherence near 70 K. A third characteristic temperature, the single-impurity Kondo temperature $T_K$≊370 K, is derived from the resistivity data at high temperatures.