Abstract
The high pressure structural and electronic evolution of bulk , an important transition metal layered dichalchogenide, is currently under active investigation, particularly in search of superconductivity. Recent theoretical and experimental work predicted and verified a layer sliding structural transition at 20 GPa and a band overlap semiconductor-semimetal transition in the same pressure range. The poorly metallic and nonsuperconducting structure is known to persist up to a pressure of 81 GPa, but properties at higher pressures remain experimentally unknown. Here we predict, with a first-principles evolutionary search, that major structural and electronic transformations should take place in equilibrium at higher pressures near 130–140 GPa. The main motif is a decomposition into MoS + S, also heralded in a small bimolecular cell by the appearance of a metastable nonlayered metallic structure with space group . Unlike semimetallic , the new high pressure phases are expected to be fully metallic and superconducting with higher critical temperatures than even alkali-intercalated .
1 More- Received 3 December 2014
- Revised 24 February 2015
DOI:https://doi.org/10.1103/PhysRevB.91.144113
©2015 American Physical Society