Tunable structural phase transition and superconductivity in the Weyl semimetal Mo1-x Wx Te2

Abstract

The relationship among structural transition, superconductivity, and doping in the Weyl semimetal Mo1-xWxTe2 has been established through a systematic study of the doping and pressure effects. Doping-dependent resistivity measurements at ambient pressure revealed that the structural transition temperature increases linearly with increasing W content in Mo1-xWxTe2. The observed structural transition temperature (Ts) of MoTe2 at ambient pressure is 249 K and that of WTe2 is 613 K. Temperature-dependent synchrotron X-ray diffraction measurements further confirmed the structural transition in WTe2 at ambient pressure. Pressure was found to continuously suppress the Ts in Mo0.90W0.10Te2,Mo0.60W0.40Te2, and Mo0.25W0.75Te2, and superconductivity emerges in Mo0.90W0.10Te2 and Mo0.60W0.40Te2 above 1.25 K when Ts is suppressed to a lower temperature.