Growth and characterization of high-quality single-crystalline SnTe retaining cubic symmetry down to the lowest temperature studied

Abstract

SnTe, an archetypical topological crystalline insulator, often shows a transition from a highly symmetric cubic phase to a rhombohedral structure at low temperatures. In order to achieve the cubic phase at low temperatures, we have grown SnTe employing the modified Bridgman method and studied its properties in detail. Analysis of the crystal structure using Laue diffraction and rocking curve measurements shows a high degree of single crystallinity and mosaicity of the sample. The magnetic susceptibility shows diamagnetic behavior, and the specific heat data match phonon contributions typical of a bulk insulator. Resistivity data exhibit metallic conduction similar to two-dimensional systems, and the signature of the structural transition has not been observed down to the lowest temperature studied. Detailed powder x-ray diffraction measurements show a cubic structure in the entire temperature range studied. This is supported by the angle-resolved photoemission data at low temperatures exhibiting a Dirac cone typical of a topological material. These results demonstrate that the ground state structure of SnTe can be stabilized in the cubic phase, providing a promising platform for quantum applications.