High-pressure investigations of the itinerant ferromagnet CoS2

The cubic pyrite compound CoS2 is an itinerant-electron ferromagnet with a Curie temperature of T-c = 122K. Measurements of its electrical resistivity in quasi-hydrostatic Bridgman cells were performed up to pressures of p = 15 GPa. T-c is monotonically decreased by the application of external pressure and a first-order quantum phase transition was inferred at a pressure of p(c) similar or equal to 6 GPa. The temperature dependence of the resistivity at low temperatures (T = 0.3-20 K) changes from a power-law with temperature exponent n = 2 in the ferromagnetic phase to n < 1.7 in the paramagnetic phase at pressures beyond p(c). (c) 2005 Elsevier B.V. All rights reserved.