Dynamic Investigations of Pressure-Induced Abnormal Phase Transitions in PbTiO3

The effects of pressure on phonon modes of ferroeleetrie tetragonal P4mm and paraelectric cubic Pm3m PbTiOa are systematically investigated by using first-principles simulations. The pressure-induced tetragonal-to-cubie and subsequent cubic-to-tetragonal phase transitions are the second-order transi...

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Published in中国物理快报：英文版 no. 5; pp. 138 - 141
Main Author 吴宏博 段益峰 刘坤 吕东 秦丽霞 石礼伟 唐刚
Format Journal Article
LanguageEnglish
Published 01.05.2015
Subjects
仿真系统
压力
声子模
异常
相变
立方相
第一原理
钛酸铅
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ISSN0256-307X
1741-3540
DOI10.1088/0256-307X/32/5/057701

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Summary:The effects of pressure on phonon modes of ferroeleetrie tetragonal P4mm and paraelectric cubic Pm3m PbTiOa are systematically investigated by using first-principles simulations. The pressure-induced tetragonal-to-cubie and subsequent cubic-to-tetragonal phase transitions are the second-order transitions, which are different from the phase transitions induced by temperature [Phys. Rev. Lett. 25 （1970） 167]. As pressure increases, the lowest A1 and E modes of the tetragonal phase become softer and converge to the F1u mode of the cubic phase. As pressure further increases, the lowest Flu mode first hardens and then softens again, and finally diverges into A1 and E modes. The behaviors of optical phonon modes confirm the ferroelectric-to-paraelectric-to-ferroeleetric phase transitions.
Bibliography:WU Hong-Bo,DUAN Yi-Feng, LIU Kun, LV Dong, QIN Li-Xia, SHI Li-Wei, TANG Gang（Department of Physics, China University of Mining and Technology, Xuzhou 221116）
11-1959/O4
The effects of pressure on phonon modes of ferroeleetrie tetragonal P4mm and paraelectric cubic Pm3m PbTiOa are systematically investigated by using first-principles simulations. The pressure-induced tetragonal-to-cubie and subsequent cubic-to-tetragonal phase transitions are the second-order transitions, which are different from the phase transitions induced by temperature [Phys. Rev. Lett. 25 （1970） 167]. As pressure increases, the lowest A1 and E modes of the tetragonal phase become softer and converge to the F1u mode of the cubic phase. As pressure further increases, the lowest Flu mode first hardens and then softens again, and finally diverges into A1 and E modes. The behaviors of optical phonon modes confirm the ferroelectric-to-paraelectric-to-ferroeleetric phase transitions.
ISSN:0256-307X
1741-3540
DOI:10.1088/0256-307X/32/5/057701