Exploring anharmonic lattice dynamics and dielectric relations in niobate perovskites from first-principles self-consistent phonon calculations
Abstract Group I niobates (KNbO3 and NaNbO3) are promising lead-free alternatives for high-performance energy storage applications. Despite their potential, their complex phase transitions arising from temperature-dependent phonon softening and anharmonic effects on dielectric properties remain poor...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Nature Portfolio
2023-08-01
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| Series: | npj Computational Materials |
| Online Access: | https://doi.org/10.1038/s41524-023-01110-8 |
| _version_ | 1797557778684837888 |
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| author | Kwangrae Kim Woohyun Hwang Seung-Hyun Victor Oh Aloysius Soon |
| author_facet | Kwangrae Kim Woohyun Hwang Seung-Hyun Victor Oh Aloysius Soon |
| author_sort | Kwangrae Kim |
| collection | DOAJ |
| description | Abstract Group I niobates (KNbO3 and NaNbO3) are promising lead-free alternatives for high-performance energy storage applications. Despite their potential, their complex phase transitions arising from temperature-dependent phonon softening and anharmonic effects on dielectric properties remain poorly explored. In this study, we employ density-functional theory (DFT) and self-consistent phonon (SCP) calculations to investigate finite-temperature phonons in cubic niobate perovskites. To include explicit anharmonic vibrational effects, SCP frequencies are shifted by the bubble self-energy correction within the quasiparticle (QP) approximation, providing precise descriptions of phonon softening in these strongly anharmonic solids. We further calculate the static dielectric constant of KNbO3 and NaNbO3 as a function of temperature using the Lyddane-Sachs-Teller (LST) relation and QP-corrected phonon dispersions. Our theoretical results align with experimental data, offering reliable temperature-dependent phonon dispersions while considering anharmonic self-energies and thermal expansion effects, enhancing our understanding of the complex relations between lattice vibrations and phase transitions in these anharmonic oxides. |
| first_indexed | 2024-03-10T17:21:00Z |
| format | Article |
| id | doaj.art-076aa136203e4da0944436b03a14e67c |
| institution | Directory Open Access Journal |
| issn | 2057-3960 |
| language | English |
| last_indexed | 2024-03-10T17:21:00Z |
| publishDate | 2023-08-01 |
| publisher | Nature Portfolio |
| record_format | Article |
| series | npj Computational Materials |
| spelling | doaj.art-076aa136203e4da0944436b03a14e67c2023-11-20T10:19:21ZengNature Portfolionpj Computational Materials2057-39602023-08-019111010.1038/s41524-023-01110-8Exploring anharmonic lattice dynamics and dielectric relations in niobate perovskites from first-principles self-consistent phonon calculationsKwangrae Kim0Woohyun Hwang1Seung-Hyun Victor Oh2Aloysius Soon3Department of Materials Science & Engineering, Yonsei UniversityDepartment of Materials Science & Engineering, Yonsei UniversityDepartment of Materials Science & Engineering, Yonsei UniversityDepartment of Materials Science & Engineering, Yonsei UniversityAbstract Group I niobates (KNbO3 and NaNbO3) are promising lead-free alternatives for high-performance energy storage applications. Despite their potential, their complex phase transitions arising from temperature-dependent phonon softening and anharmonic effects on dielectric properties remain poorly explored. In this study, we employ density-functional theory (DFT) and self-consistent phonon (SCP) calculations to investigate finite-temperature phonons in cubic niobate perovskites. To include explicit anharmonic vibrational effects, SCP frequencies are shifted by the bubble self-energy correction within the quasiparticle (QP) approximation, providing precise descriptions of phonon softening in these strongly anharmonic solids. We further calculate the static dielectric constant of KNbO3 and NaNbO3 as a function of temperature using the Lyddane-Sachs-Teller (LST) relation and QP-corrected phonon dispersions. Our theoretical results align with experimental data, offering reliable temperature-dependent phonon dispersions while considering anharmonic self-energies and thermal expansion effects, enhancing our understanding of the complex relations between lattice vibrations and phase transitions in these anharmonic oxides.https://doi.org/10.1038/s41524-023-01110-8 |
| spellingShingle | Kwangrae Kim Woohyun Hwang Seung-Hyun Victor Oh Aloysius Soon Exploring anharmonic lattice dynamics and dielectric relations in niobate perovskites from first-principles self-consistent phonon calculations npj Computational Materials |
| title | Exploring anharmonic lattice dynamics and dielectric relations in niobate perovskites from first-principles self-consistent phonon calculations |
| title_full | Exploring anharmonic lattice dynamics and dielectric relations in niobate perovskites from first-principles self-consistent phonon calculations |
| title_fullStr | Exploring anharmonic lattice dynamics and dielectric relations in niobate perovskites from first-principles self-consistent phonon calculations |
| title_full_unstemmed | Exploring anharmonic lattice dynamics and dielectric relations in niobate perovskites from first-principles self-consistent phonon calculations |
| title_short | Exploring anharmonic lattice dynamics and dielectric relations in niobate perovskites from first-principles self-consistent phonon calculations |
| title_sort | exploring anharmonic lattice dynamics and dielectric relations in niobate perovskites from first principles self consistent phonon calculations |
| url | https://doi.org/10.1038/s41524-023-01110-8 |
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