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Title: Mechanical and thermal properties of h-MX{sub 2} (M = Cr, Mo, W; X = O, S, Se, Te) monolayers: A comparative study

Using density functional theory, we obtain the mechanical and thermal properties of MX{sub 2} monolayers (where M = Cr, Mo, W and X = O, S, Se, Te). The Γ-centered phonon frequencies (i.e., A{sub 1}, A{sub 2}{sup ″}, E′, and E″), relative frequency values of A{sub 1}, and E′ modes, and mechanical properties (i.e., elastic constants, Young modulus, and Poisson's ratio) display a strong dependence on the type of metal and chalcogenide atoms. In each chalcogenide (metal) group, transition-metal dichalcogenides (TMDCs) with W (O) atom are found to be much stiffer. Consistent with their stability, the thermal expansion of lattice constants for TMDCs with O (Te) is much slower (faster). Furthermore, in a heterostructure of these materials, the difference of the thermal expansion of lattice constants between the individual components becomes quite tiny over the whole temperature range. The calculated mechanical and thermal properties show that TMDCs are promising materials for heterostructures.
Authors:
;  [1] ;  [2]
  1. Department of Physics, University of Antwerp, 2610 Antwerpen (Belgium)
  2. Department of Mechanical Engineering, Faculty of Engineering, Anadolu University, Eskisehir TR 26555 (Turkey)
Publication Date:
OSTI Identifier:
22300182
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 104; Journal Issue: 20; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ATOMS; CHALCOGENIDES; CHROMIUM COMPOUNDS; COMPUTERIZED SIMULATION; DENSITY FUNCTIONAL METHOD; LATTICE PARAMETERS; LAYERS; MECHANICAL PROPERTIES; MOLYBDENUM COMPOUNDS; OXIDES; SELENIDES; STABILITY; SULFIDES; TELLURIDES; THERMAL EXPANSION; THERMODYNAMIC PROPERTIES; TRANSITION ELEMENT COMPOUNDS; TUNGSTEN COMPOUNDS; YOUNG MODULUS