材料期刊网

The structural, elastic properties and the pressure-induced phase transition of 'half-Heusler' alloy CoVSb are investigated using the pseudopotential plane wave method within the generalized gradient approximation (GGA). The calculated structural parameters are in good agreement with the available experimental and theoretical data. The elastic constants and their pressure dependences of 'half-Heusler' cubic CoVSb are calculated using the static finite strain technique, and are presented for the first time together with the theoretical pressure-induced phase transition. The research of phase transition and the calculations of electronic structures show that the 'half-Heusler' cubic CoVSb transforms to normal hexagonal CoVSb with atomic configurations I and II at about 13.5 and 78.0 GPa, respectively at OK. Combining the analysis of ground-state structures, it is concluded that the 'half-Heusler' cubic CoVSb mainly transforms to hexagonal CoVSb with atomic configuration I at a relative lower pressure. (C) 2010 Elsevier B.V. All rights reserved.