The Local Structure of Ferroelectric Pb1-xGexTe

Published

May 1, 1999

Author(s)

Bruce D. Ravel, Eric J. Cockayne, K M. Rabe

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

Pub Type

Journals

Keywords

EAFS, ground state structure, Pb_1-xGe_xTe

Citation

Ravel, B. , Cockayne, E. and Rabe, K. (1999), The Local Structure of Ferroelectric Pb_1-xGe_xTe, Journal of Synchrotron Radiation (Accessed June 9, 2023)