High pressure structural phase transition in uranium monochalcogenides

Srivastava, Anurag; Kumari, Samiksha; Gupta, B. R. K.

doi:10.1080/01411590903528413

Cited by 7 publications

(4 citation statements)

References 17 publications

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“…The underlined term in the above expressions is essential for explaining Cauchy's discrepancy in solids. We should note that the expression reported in earlier works [17,18,23,24] actually leads to C 12 =C 44 , while the results given in those works show that C 12 ≠C 44 . On the other hand, the expressions derived by us are capable of correctly explaining Cauchy's discrepancy (C 12 − C 44 ≠0) in terms of the modified CTI parameter.…”

Section: Second-order Elastic Constants (Soecs)mentioning

confidence: 64%

“…The results are qualitatively and quantitatively better than those obtained in earlier works [9,[15][16][17][18], and support the effectiveness and validity of the modified expressions. The expressions of Gour et al [17,18], Varshney et al [23], and Srivastava et al [24] show that C 12 − C 44 =0, while their results show different values of C 12 and C 44 , so their results are not reliable.…”

Section: Elastic Propertiesmentioning

confidence: 65%

“…Recently, Gour et al [17,18], Varshney et al [23], and Srivastava et al [24] computed a few crystal properties of Eu and some other RECs, but many of these-especially the elastic properties, Cauchy's discrepancy, and the pressure variation-are not explained very well due to the exclusion of covalency and CTI from the expressions for the elastic moduli. These interactions are responsible for the Coulomb screening due to the delocalized f electrons in the rare-earth ion.…”

Section: Introductionmentioning

confidence: 97%

“…The inclusion of the covalency effect improves the accuracy of the predicted values of the crystal properties under high pressure because this effect increases with pressure. The models used to explain the crystal properties in earlier works [17,18,23,24] were rather basic, and excluding CTI, covalency, and zero-point (ZP) energy affected their potentials, which play an important role in defining the crystal properties of RECs, thus affecting the results obtained from such models. Their expressions for elastic moduli had C 12 =C 44 , which contradicted their results, as they showed Cauchy's discrepancy (C 12 ≠C 44 ).…”

Section: Introductionmentioning

confidence: 99%

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High-pressure phase transition and thermoelastic properties of europium chalcogenides

Gupta

Singh

2011

J Mol Model

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The pressure-induced crystal properties of Eu chalcogenides were investigated using two different models: a modified charge-transfer potential model consisting of Coulomb screening due to the delocalization of the f electron of the rare earth atom, and modified by covalency and zero-point energy effects along with attractive and repulsive interactions; and a charge-transfer model that excluded the covalency and zero-point energy effects in the previous model. Both models were used to visualize the effect of covalency on the mechanism of interaction of the constituent atoms. Eu chalcogenides transform from the Fm3m to the Pm3m phase under the influence of sufficient pressure (P(T) = 39.52, 21.01, 14.31, and 10.58 GPa), and their equations of state indicated decreases in volume during this phase transition of 6.38, 12.32, 12.76, and 11.15%, respectively, for EuO, EuS, EuSe, and EuTe. The results obtained from the models were in good agreement with corresponding experimental data. The elastic constants and Debye temperatures were also computed at normal and high pressures. Both of the models were found to be capable of successfully explaining these properties.

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Section: Second-order Elastic Constants (Soecs)mentioning

confidence: 64%