Combined EXAFS and First-Principles Theory Study of Pb1-xGexTe

Published

December 1, 1999

Author(s)

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

Abstract

The narrow band-gap semiconductor Pb_1-xGe_xTe has a low-temperature ferroelectric rhombohedral phase whose average structure is a distorted rocksalt structure. We have measured the Extended X-Ray-Absorption Fine-Structure (EXAFS) spectra of Pb_1-xGe_xTe with x {nearly equal to} 0.3 at the Ge and Te K edges and at the Pb L_III edge. Guided by first-principles calculations, we create a model for the local structure as a distortion from the ideal rock salt structure. By co-refining the spectra from these edges, we demonstrate that the data are consistent with our fitting model and we directly measure several secondary structural distortions predicted by the theory. This work demonstrates a powerful approach to the determination of local structures in complex materials by using first-principles calculations in conjunction with EXAFS measurements.

Citation

Physical Review B (Condensed Matter and Materials Physics)

Volume

60

Issue

No. 21

Pub Type

Journals

Keywords

EXAFS, ferroelectric, functional theory, local density

Citation

Ravel, B. , Cockayne, E. , Newville, E. and Rabe, K. (1999), Combined EXAFS and First-Principles Theory Study of Pb_1-xGe_xTe, Physical Review B (Condensed Matter and Materials Physics) (Accessed December 30, 2024)