# Kwon Group, Physics, Kyung Hee University

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lab:research:tmdichal-01

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 lab:research:tmdichal-01 [2014/11/20 21:37]ykkwon [Single-layer MX2] lab:research:tmdichal-01 [2014/12/31 15:34] (current)seoung-hun_kang Both sides previous revision Previous revision 2014/12/31 15:34 seoung-hun_kang 2014/11/20 21:37 ykkwon [Single-layer MX2] 2014/11/09 01:41 external edit 2014/12/31 15:34 seoung-hun_kang 2014/11/20 21:37 ykkwon [Single-layer MX2] 2014/11/09 01:41 external edit Line 1: Line 1: ==== Single-layer MX$_2$ ==== ==== Single-layer MX$_2$ ==== - Single-layer MX$_2$ ​blah blah... + We investigate the structural, electronic properties of MX$_2$. + (M=Ti, V, Cr, Zr, Nb, Mo, Hf, Ta, W) (X=S, Se) and their phase + transition. We calculate the relative stability of two phase + structures (octahedral-T and trigonal-H) determined by considering + relative positions of X. We find interesting phase existence for + the each group in the periodic table. The stable phase structure + of IV-group (Ti, Zr, Hf) is octahedral, while VI-group (Cr, Mo, W) + is trigonal, and V-group (V, Nb, Ta) is possible two phase structures. + Two phase structures of MX$_2$ ​have a same total energy at the same + lattice constant near the each most stable lattice constant. + From these results, we also study activation energy barriers + at the various lattice constants such as from stable T phase to H phase, + same total energy, and from stable H to T. Interestingly + we find that the activation energy barrier is small at the small and + large lattice constants for the stable lattice constants. + It means that the phase transition occurs by compressive and tensile strains.