Pressure-induced structural phase transition and electrical properties of Cu2S

The structural phase transition and electrical properties of Cu2S have been investigated by X-ray diffraction and electrical resistance measurements at pressures up to 41.3 GPa in diamond anvil cell. A new high pressure phase is found above 22.3 GPa, which probably has a tetragonal structure. It is observed that the electrical resistance exhibits an insulating behavior at high pressures and low temperature. After the pressure is released, the high pressure phase transforms back to original monoclinic phase. This study sheds light on the electrical transport properties of Cu2S, as well as to improve our understanding of its high pressure phase transition behavior.