Pressure-induced Quantum Phase Transition in Cr_1-xV_x Alloys

Abstract

  The electrical resistivities and Hall effect of Cr_1-xV_x alloys(x<0.04) were measured at high pressure. The Néel temperature T_N of x = 0.015, 0.032 and 0.035 was found to disappear at corresponding P_c of 5.6 GPa, 1.1 GPa and 0.7 GPa, respectively. The Hall coefficients of x = 0.032 and 0.035 demonstrated a discontinuous change around P_c, which implies a quantum phase transition induced by high pressure. We found that the exponents in the power law of resistivity of x = 0.015 had an anomaly around P_c, which means that the large quantum fluctuations affect the resistivity even at high temperature. A possibility of superconductivity is explored near P_c for x = 0.032. A slight decrease in the ρ(T) curve was observed below 1 K at high pressure. The origins for that are briefly discussed.