FERROELECTRICITY IN THE IV-VI COMPOUNDS - Download this document for free, or read online. Document in PDF available to download.

Abstract : Preliminary results are reported of calculations aimed at a theoretical study of the cubic-rhombohedral phase transition in GeTe, SnTe and GeTe-SnTe compounds. The present calculations are being carried out within the context of the recently developed self-consistent phonon approximation. The application of this theory to displacive transitions in solids has been stimulated by the recent success of the self-consistent phonon approximation in yielding a qualitatively correct temperature dependence of the thermal expansivity of the rare gas solids neon and argon. Two major questions to be discussed in the light of the present calculations are : 1 Does the self-consistent phonon approximation yield a qualitatively correct temperature dependence of the long-wavelength phonons near the displacive transition in cubic diatomic ferroelectric models ? 2 Will pseudo-potential theory as modified to include the effects of covalent bonding provide an indirect ion-ion interaction which will adequately describe the lattice dynamics of SnTe and GeTe ?

Author: Nelson Gillis

Source: https://hal.archives-ouvertes.fr/


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