Local structural distortions in SnTe investigated by EXAFS

P Fornasini; R Grisenti; M Dapiaggi; G Agostini

doi:10.1088/1361-648X/ac0082

Local structural distortions in SnTe investigated by EXAFS

J Phys Condens Matter. 2021 Jun 9;33(29). doi: 10.1088/1361-648X/ac0082.

Authors

P Fornasini¹, R Grisenti¹, M Dapiaggi², G Agostini³

Affiliations

¹ Dipartimento di Fisica - Università di Trento, Via Sommarive 14, I-38123 Povo (Trento), Italy.
² Dipartimento di Scienze della Terra, Università di Milano, I-20133 Milano, Italy.
³ ESRF, Grenoble, France.

PMID: 33979790
DOI: 10.1088/1361-648X/ac0082

Abstract

Extended x-ray absorption fine structure (EXAFS) has been measured at theKedge of Sn in SnTe in the temperature range from 5 to 480 K. EXAFS results are consistent with the presence of a local rhombohedral distortion in the full temperature range from 5 to 300 K, even well above the ferroelectric transition temperature, suggesting a partial order-disorder character of the transition. At and above 300 K, the anomalous behaviour of the third and fourth EXAFS cumulants reveals a modification of the anharmonicity of the effective pair potential, possibly connected with the softening of high frequency modes or to the presence of multiple phases.

Keywords: EXAFS; ferroelectric transition; local distortions; tin telluride.