Pressure-Induced Semiconductor-Semimetal Transition in Rb0.8Fe1.6S2

The transport and magnetic properties of the Rb0.8Fe1.6S2 crystal have been studied under quasihydrostatic compression to a pressure of 40.5 GPa in diamond anvil cells. A semiconductor-semimetal electronic transition has been detected at a pressure of about 15 GPa. In addition, the disappearance of the magnetic order down to a temperature of 3 K has been found at a pressure of 24 GPa. It has been shown that, in contrast to a similar selenium compound Rb0.8Fe1.6Se2, superconductivity in Rb0.8Fe1.6S2 sulfide does not appear down to the lowest temperatures even at an external pressure of 40.5 GPa.