High pressure phase transition and elastic behaviour of lanthanum monochalcogenides |
| |
Authors: | D. C. Gupta G. S. Raypuria |
| |
Affiliation: | (1) Condensed Matter Theory Group, School of Studies in Physics, Jiwaji University, Gwalior, 474 011, MP, India |
| |
Abstract: | The Phase transition and elastic properties of La-monochalcogenides have been investigated under pressure by means of a modified charge-transfer potential model which incorporates the Coulomb interaction modified by Coulomb screening due to the delocalization of electron of rare-earth atom leading to many-body interactions, covalency effect and overlap repulsion extended up to second-nearest neighbours. Under high pressure the coordination increases and they transform from rock-salt to CsCl structure. The calculated values of cohesive energy, lattice constant, phase transition pressure, relative volume collapse, harmonic and anharmonic elastic moduli and their first- and second-order pressure derivatives agree well with the available measured data and better than those computed by earlier workers. Present model is capable of explaining the Cauchy’s discrepancy correctly. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|