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Publication Citation: The Local Structure of Ferroelectric Pb1-xGexTe

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Author(s): Bruce D. Ravel; Eric J. Cockayne; K M. Rabe;
Title: The Local Structure of Ferroelectric Pb1-xGexTe
Published: May 01, 1999
Abstract: The narrow band-gap semiconductor Pb_{1-x}Ge_xTe has a low-temperature ferroelectric rhombohedral phase whose average structure is a distorted rock salt structure. We have measured the Extended X-ray-Absorption Fine-Structure spectra of Pb_{1-x}Ge_xTe with x \approx 0.3 at the Ge and Te K edges and at the Pb L3 edge. By co-refining the spectra from these three edges, we have accurately determined the ground state structure of this material. We compare these results with recent first-principles density-functional calculations of total energies and find that these first-principles calculations of the ground state structure are in good agreement with the measured structure. Specifically we find a large lattice relaxation around the Ge site and a large displacement of the Ge atom from its nominal lattice position.
Citation: Journal of Synchrotron Radiation
Volume: 6
Pages: pp. 567 - 569
Keywords: EAFS,ground state structure,Pb1-xGexTe
Research Areas: Ceramics