Novel Pressure Induced Structural Phase Transition in AgSbTe$_{2}$

TL;DR

This study reveals a novel high-pressure phase transition in AgSbTe₂, involving a B1 to B2 structural change with an intermediate amorphous phase, confirmed by experiments and DFT calculations.

Contribution

First report of a pressure-induced B1 to B2 transition with an intermediate amorphous phase in AgSbTe₂, expanding understanding of phase behavior in this family.

Findings

B1 to B2 transition observed at high pressure

Intermediate amorphous phase between 17-26 GPa

DFT calculations agree with experimental results

Abstract

We report a novel high pressure structural sequence for the functionally graded thermoelectric, narrow band gap semiconductor AgSbTe$_{2}$, using angle dispersive x-ray diffraction in a diamond anvil cell with synchrotron radiation at room temperature. The compound undergoes a B1 to B2 transition; the transition proceeds through an intermediate amorphous phase found between 17-26 GPa that is quenchable down to ambient conditions. The pressure induced structural transition observed in this compound is the first of its type reported in this ternary cubic family, and it is new for the B1-B2 transition pathway reported to date. Density Functional Theory (DFT) calculations performed for the B1 and B2 phases are in good agreement with the experimental results.