title: Pressure evolution of the potential barriers of phase transition of MoS2, MoSe2 and MoTe2.
abstract: Two-dimensional crystals with weak layer interactions, such as twisted graphene, have been a focus of research recently. As a representative example, transitional metal dichalcogenides show a lot of fascinating properties due to stacking orders and spin-orbit coupling. We analyzed the dynamic energy barrier of possible phase transitions in MoX2 (X = S, Se and Te) with first-principles methods. In the structural transition from 2Hc to 2Ha, the energy barrier is found to be increased following an increase of pressure which is different from the phase transition in usual semiconductors. Among MoS2, MoSe2 and MoTe2, the energy barrier of MoS2 is the lowest and the stability of both 2Hc and 2Ha is reversed under pressure for MoS2. It is found that the absence of a phase transition in MoSe2 and MoTe2 is due to the competition between van der Waals interaction of layers and the coulomb interaction of Mo and X in nearest-neighbor layer of Mo in both phases.
authors.affiliation: College of Materials Science and Engineering, Jilin University, Changchun 130012, China. xffan@jlu.edu.cn wtzheng@jlu.edu.cn.
authors.forename: Xaiofeng
authors.initials: X
authors.lastname: Fan
authors.affiliation: Department of Physics and Astronomy, University of Missouri, Columbia, Missouri 65211-7010, USA.
authors.forename: David J
authors.initials: DJ
authors.lastname: Singh
authors.affiliation: College of Materials Science and Engineering, Jilin University, Changchun 130012, China. xffan@jlu.edu.cn wtzheng@jlu.edu.cn.
authors.forename: Q
authors.initials: Q
authors.lastname: Jiang
authors.affiliation: College of Materials Science and Engineering, Jilin University, Changchun 130012, China. xffan@jlu.edu.cn wtzheng@jlu.edu.cn.
authors.forename: W T
authors.initials: WT
authors.lastname: Zheng