On the ambient conditions crystal structure of AgSbTe2

TL;DR

This study combines multiple experimental techniques and first-principles calculations to conclusively determine the rhombohedral R-3m crystal structure of AgSbTe2, resolving a long-standing debate.

Contribution

It provides a comprehensive multi-method approach that clarifies the crystal structure of AgSbTe2, which was previously unresolved by diffraction alone.

Findings

Raman and NMR data support the R-3m phase

Agreement between experimental and calculated spectra confirms structure

Resolves a 60-year debate about AgSbTe2's crystal structure

Abstract

We present a combined X-ray and neutron diffraction, Raman spectroscopy, and 121Sb NMR studies of AgSbTe2, supported by first-principles calculations aiming to elucidate its crystal structure. While diffraction methods cannot unambiguously resolve the structure, Raman and NMR data, together with electric field gradient calculations, strongly support the rhombohedral R-3m phase. Moreover, the agreement between experimental and calculated Raman spectra further corroborates this result, resolving the 60-year sold debate about the exact crystal structure of the AgSbTe2 compound.