{"title":"Elastic constants of NaCl crystal at high pressures and high temperatures based on thermodynamics of elastic deformation","authors":"Jolly Sharma, B.S. Sharma","doi":"10.1016/j.cocom.2025.e01074","DOIUrl":null,"url":null,"abstract":"<div><div>Elastic constants viz. C<sub>11</sub>, C<sub>12</sub> and C<sub>44</sub> for a cubic solid such as NaCl crystal with rock-salt structure are determined at high pressures and high temperatures using Tallon's model based on thermodynamics of elastic deformation. The parameters used by Tallon are represented by the modified Anderson-Grüneisen parameters related to the isothermal and isobaric volume derivatives of elastic constants. Values of elastic constants computed in the present study are found to increase and decrease, respectively, with the increase in pressure and temperature. Values of bulk modulus, shear moduli, Young's modulus, Poisson's ratio and velocities of shear waves have been computed for NaCl at different pressures and temperatures. The results for isobaric variations of elastic moduli with temperature have been used to discuss the melting behaviour of NaCl at high pressures in terms of anharmonicity and mechanical or elastic instability of solids at high temperatures. The elastic stability of NaCl has been discussed in terms of the Born criteria and the stability triangle.</div></div>","PeriodicalId":46322,"journal":{"name":"Computational Condensed Matter","volume":"44 ","pages":"Article e01074"},"PeriodicalIF":3.9000,"publicationDate":"2025-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Computational Condensed Matter","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2352214325000735","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"PHYSICS, CONDENSED MATTER","Score":null,"Total":0}
引用次数: 0
Abstract
Elastic constants viz. C11, C12 and C44 for a cubic solid such as NaCl crystal with rock-salt structure are determined at high pressures and high temperatures using Tallon's model based on thermodynamics of elastic deformation. The parameters used by Tallon are represented by the modified Anderson-Grüneisen parameters related to the isothermal and isobaric volume derivatives of elastic constants. Values of elastic constants computed in the present study are found to increase and decrease, respectively, with the increase in pressure and temperature. Values of bulk modulus, shear moduli, Young's modulus, Poisson's ratio and velocities of shear waves have been computed for NaCl at different pressures and temperatures. The results for isobaric variations of elastic moduli with temperature have been used to discuss the melting behaviour of NaCl at high pressures in terms of anharmonicity and mechanical or elastic instability of solids at high temperatures. The elastic stability of NaCl has been discussed in terms of the Born criteria and the stability triangle.