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Anharmonic effects in the A15 compounds induced by sublattice distortions

Z. W. Lu·B. M. Klein
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Abstract

We demonstrate that elastic anomalies and lattice instabilities in the the A15 compounds are describable in terms of first-principles LDA electronic structure calculations. We show that at T=0 V_3Si, V_3Ge, and Nb_3Sn are intrinsically unstable against shears with elastic moduli C_11-C_12 and C_44, and that the zone center phonons, Gamma_2 and Gamma_12, are either unstable or extremely soft. We demonstrate that sublattice relaxation (internal strain) effects are key to understanding the behavior of the A15 materials.

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Z. W. Lu, B. M. Klein. 1997-07-07. Anharmonic effects in the A15 compounds induced by sublattice distortions. https://doi.org/10.1103/physrevlett.79.1361

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