The curious case of the structural phase transition in SnSe insights from neutron total scattering
Year: 2023
Type: article
Abstract: At elevated temperatures SnSe is reported to undergo a structural transition from the low symmetry orthorhombic GeS-type to a higher symmetry orthorhombic TlI-type. Although increasing symmetry should likewise increase lattice thermal conductivity, many experiments on single crystals and polycrystalline materials indicate that this is not the case. Here we present temperature dependent analysis of time-of-flight (TOF) neutron total scattering data in combination with theoretical modeling to probe the local to long-range evolution of the structure. We report that while SnSe is well characterized on average within the high symmetry space group above the transition, over length scales of a few unit cells SnSe remains better characterized in the low symmetry GeS-type space group. Our finding from robust modeling provides further insight into the curious case of a dynamic order-disorder phase transition in SnSe, a model consistent with the soft-phonon picture of the high thermoelectric power above the phase transition.
Source: Nature Communications
Institutions: Oak Ridge National Laboratory, University of Tennessee at Knoxville, Florida State University, National High Magnetic Field Laboratory, Brookhaven National Laboratory, National Synchrotron Light Source II, Centre National de la Recherche Scientifique, Université Bourgogne Franche-Comté, Laboratoire Interdisciplinaire Carnot de Bourgogne, Florida A&M University - Florida State University College of Engineering
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $6,290
Awards: G1019100964, G1138554163, G121915436, G1645119126, National High Magnetic Field Laboratory Renewal 2018-2022, G203625172, G2411683797, G2988778103, G3049477530, G354028113, G3560959519, G3945850812, G410635398, G4423657506, Chalcogenides Superconductors: Nonconventional Superconductivity in New Phases, G5449040465, G6010147111, G6486853205, G675320460, G6911681599, G7214215584, G7541729576, G807938293, ISITE « BFC, G8269158468, G8906985441
OpenAlex ID: W4379207683