Ferroelectric phases and phase transitions in CsGeBr$_3$ induced by mechanical load

Fuente: arXiv
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Main Authors: Townsend, Joshua, Kashikar, Ravi, Lisenkov, S., Ponomareva, I.
Format: Preprint
Published: 2024
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author Townsend, Joshua
Kashikar, Ravi
Lisenkov, S.
Ponomareva, I.
author_facet Townsend, Joshua
Kashikar, Ravi
Lisenkov, S.
Ponomareva, I.
contents First-principles-based atomistic simulations are used to reveal ferroelectric phases and phase transitions induced in a semiconductor ferroelectric, CsGeBr$_3$, by external loads: hydrostatic pressure, uniaxial and biaxial stresses, and misfit strain. Hydrostatic pressure was found to suppress the Curie point at the rate -0.45$T_C(0)$ K/GPa, where $T_C(0)$ is the zero pressure Curie temperature. Stresses and misfit strains were found to induce additional ferroelectric phase transitions and phases not available under normal conditions. We find that tensile load significantly enhances both the Curie temperature and spontaneous polarization, while compressive load has the opposite effect but with the difference that the Curie temperature is only slightly suppressed. The isothermal dependencies of polarization on pressure and stresses are highly nonlinear, which could result in large nonlinear piezoelectric responses. The phase diagrams reveal the diversity of the phases accessible through mechanical load, which include tetragonal, orthorhombic and monoclinic symmetries in addition to the rhombohedral and cubic ones realizable under normal conditions. We believe that this work reveals the potential of Ge-based halide perovskites for applications in energy converting devices, which is especially significant in the current pursuit of environmental friendly lead-free technologies.
format Preprint
id arxiv_https___arxiv_org_abs_2403_10421
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Ferroelectric phases and phase transitions in CsGeBr$_3$ induced by mechanical load
Townsend, Joshua
Kashikar, Ravi
Lisenkov, S.
Ponomareva, I.
Materials Science
First-principles-based atomistic simulations are used to reveal ferroelectric phases and phase transitions induced in a semiconductor ferroelectric, CsGeBr$_3$, by external loads: hydrostatic pressure, uniaxial and biaxial stresses, and misfit strain. Hydrostatic pressure was found to suppress the Curie point at the rate -0.45$T_C(0)$ K/GPa, where $T_C(0)$ is the zero pressure Curie temperature. Stresses and misfit strains were found to induce additional ferroelectric phase transitions and phases not available under normal conditions. We find that tensile load significantly enhances both the Curie temperature and spontaneous polarization, while compressive load has the opposite effect but with the difference that the Curie temperature is only slightly suppressed. The isothermal dependencies of polarization on pressure and stresses are highly nonlinear, which could result in large nonlinear piezoelectric responses. The phase diagrams reveal the diversity of the phases accessible through mechanical load, which include tetragonal, orthorhombic and monoclinic symmetries in addition to the rhombohedral and cubic ones realizable under normal conditions. We believe that this work reveals the potential of Ge-based halide perovskites for applications in energy converting devices, which is especially significant in the current pursuit of environmental friendly lead-free technologies.
title Ferroelectric phases and phase transitions in CsGeBr$_3$ induced by mechanical load
topic Materials Science
url https://arxiv.org/abs/2403.10421