Octahedral Tilt-Driven Phase Transitions in BaZrS 3 Chalcogenide Perovskite

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Bibliographic Details
Title: Octahedral Tilt-Driven Phase Transitions in BaZrS 3 Chalcogenide Perovskite
Authors: Kayastha, Prakriti, Fransson, Erik, 1990, Erhart, Paul, 1978, Whalley, Lucy
Source: Journal of Physical Chemistry Letters. 16:2064-2071
Subject Terms: Phase transitions, Chemical structure, Perovskites, Particulate matter, Diffraction
Description: Chalcogenide perovskites are lead-free materials for potential photovoltaic or thermoelectric applications. BaZrS3 is the most-studied member of this family due to its superior thermal and chemical stability, desirable optoelectronic properties, and low thermal conductivity. Phase transitions in BaZrS3 remain underexplored in the literature, as most experimental characterizations of this material have been performed at ambient conditions where the orthorhombic Pnma phase is reported to be stable. In this work, we study the dynamics of BaZrS3 across a range of temperatures and pressures using an accurate machine learning interatomic potential trained with data from hybrid density functional theory calculations. At 0 Pa, we find a first-order phase transition from the orthorhombic to tetragonal I4/mcm phase at 610 K, and a second-order transition from the tetragonal to the cubic Pm3̅m phase at 880 K. The tetragonal phase is stable over a larger temperature range at higher pressures. To confirm the validity of our model we compare our results with a range of published experimental data and report a prediction for the X-ray diffraction pattern as a function of temperature.
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Access URL: https://research.chalmers.se/publication/545282
https://research.chalmers.se/publication/545282/file/545282_Fulltext.pdf
Database: SwePub
Description
Abstract:Chalcogenide perovskites are lead-free materials for potential photovoltaic or thermoelectric applications. BaZrS3 is the most-studied member of this family due to its superior thermal and chemical stability, desirable optoelectronic properties, and low thermal conductivity. Phase transitions in BaZrS3 remain underexplored in the literature, as most experimental characterizations of this material have been performed at ambient conditions where the orthorhombic Pnma phase is reported to be stable. In this work, we study the dynamics of BaZrS3 across a range of temperatures and pressures using an accurate machine learning interatomic potential trained with data from hybrid density functional theory calculations. At 0 Pa, we find a first-order phase transition from the orthorhombic to tetragonal I4/mcm phase at 610 K, and a second-order transition from the tetragonal to the cubic Pm3̅m phase at 880 K. The tetragonal phase is stable over a larger temperature range at higher pressures. To confirm the validity of our model we compare our results with a range of published experimental data and report a prediction for the X-ray diffraction pattern as a function of temperature.
ISSN:19487185
DOI:10.1021/acs.jpclett.4c03517