First-principles study of phase transition in cadmium titanate by molecular dynamics incorporating nuclear quantum effects

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Hauptverfasser: Kanayama, Kansei, Toyoura, Kazuaki
Format: Preprint
Veröffentlicht: 2024
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author Kanayama, Kansei
Toyoura, Kazuaki
author_facet Kanayama, Kansei
Toyoura, Kazuaki
contents First-principles molecular dynamics (FPMD) simulations were applied for the paraelectric-ferroelectric phase transition in the perovskite-type cadmium titanate, CdTiO3. Since the phase transition is reported to occur at the low temperature around 80 K, the quantum thermal bath (QTB) method was utilized in this study, which incorporates the nuclear quantum effects (NQEs). The structural evolutions in the QTB-FPMD simulations are in reasonable agreement with the experimental results, by contrast in the conventional FPMD simulations using the classical thermal bath (CTB-FPMD). According to our phonon calculations, volume expansion is the key in the stabilization of the ferroelectric phase at low temperatures, which was well reproduced in the QTB-FPMD with the NQEs. Thus, the NQEs are of importance in phase transitions at low temperatures, particularly below the room temperature, and the QTB is useful in that it incorporates the NQEs in MD simulations with low computational costs comparable to the conventional CTB.
format Preprint
id arxiv_https___arxiv_org_abs_2404_12004
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle First-principles study of phase transition in cadmium titanate by molecular dynamics incorporating nuclear quantum effects
Kanayama, Kansei
Toyoura, Kazuaki
Materials Science
First-principles molecular dynamics (FPMD) simulations were applied for the paraelectric-ferroelectric phase transition in the perovskite-type cadmium titanate, CdTiO3. Since the phase transition is reported to occur at the low temperature around 80 K, the quantum thermal bath (QTB) method was utilized in this study, which incorporates the nuclear quantum effects (NQEs). The structural evolutions in the QTB-FPMD simulations are in reasonable agreement with the experimental results, by contrast in the conventional FPMD simulations using the classical thermal bath (CTB-FPMD). According to our phonon calculations, volume expansion is the key in the stabilization of the ferroelectric phase at low temperatures, which was well reproduced in the QTB-FPMD with the NQEs. Thus, the NQEs are of importance in phase transitions at low temperatures, particularly below the room temperature, and the QTB is useful in that it incorporates the NQEs in MD simulations with low computational costs comparable to the conventional CTB.
title First-principles study of phase transition in cadmium titanate by molecular dynamics incorporating nuclear quantum effects
topic Materials Science
url https://arxiv.org/abs/2404.12004