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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
@@ Line 1: / Line 1: @@
 ==== 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.

Kwon Group, Physics, Kyung Hee University