Composition dependent phase transition and its induced hysteretic effect in the thermal conductivity of WxMo1−xTe2

Recently, transition metal dichalcogenide (TMD) materials have shown promise in electronics and optoelectronics applications. Most of their properties are closely related to their abundant structural phases and phase transitions. For more practical applications in the future, it is necessary to tune the phase transitions in this material system. Here, we demonstrate the modulation of phase transitions in miscible WxMo1−xTe2 samples by appropriate alloying. The temperature dependent thermal conductivity along the c-axis, which strongly relates to the phase structures and the defect level, has been measured using the time-domain thermoreflectance method. In addition, a tunable hysteretic effect, induced by phase transitions, is observed in both thermal and electrical transport properties and confirmed by the consistent hysteresis in the Raman spectroscopic study. This hysteretic effect can be applied to realize phase-change storage devices. Furthermore, we provide a phase diagram to illustrate the composition dependent phase transition in WxMo1−xTe2. This work demonstrates an approach to modulate phase transition and thermal hysteresis in such a TMD material system by alloying engineering.