Investigations of the pressure dependence of structural, chemical, electrical, and magnetic properties of cuprous chloride (CuCl)

Extensive x-ray, bulk-compressibility, electrical-resistivity, magnetic-susceptibility, microwave-absorption, and ESR measurements have been carried out under conditions of varying pressure and temperature on freshly prepared samples of CuCl. Based on both magnetic-susceptibility and microwave-absorption data, no evidence is found to support the existence of a superconducting transition in the interval between 300 and ∼10 K and at pressures up to about 10 GPa. Structural phase transitions have been identified at 5-6 GPa and 10-11 GPa with about 12% and 1% volume reductions, respectively. Evidence is also reported of a sluggish pressure-induced, metal-like transition which may be associated with the disproportionation reaction: 2CuCl → Cu${\mathrm{Cl}}_2$ + Cu. These results are discussed in the light of recent magnetic anomalies reported for CuCl, and explanations are proposed to explain them.