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Indexed by:期刊论文

Date of Publication:2012-04-15

Journal:JOURNAL OF APPLIED PHYSICS

Included Journals:SCIE、EI

Volume:111

Issue:8

ISSN No.:0021-8979

Abstract:To study temperature dependent elastic constants, a new computational method is proposed by combining continuum elasticity theory and first principles calculations. A Gibbs free energy function with one variable with respect to strain at given temperature and pressure was derived; hence, the minimization of the Gibbs free energy with respect to temperature and lattice parameters can be put into effective operation by using first principles. Therefore, with this new theory, anisotropic thermal expansion and temperature dependent elastic constants can be obtained for crystals with arbitrary symmetry. In addition, we apply our method to hexagonal beryllium, hexagonal diamond, and cubic diamond to illustrate its general applicability. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4704698]