Maurya, Deepam Charkhesht, Ali Nayak, Sanjeev K. Sun, Fu-Chang George, Deepu Pramanick, Abhijit Kang, Min-Gyu Song, Hyun-Cheol Alexander, Marshall M. Lou, Djamila Khodaparast, Giti A. Alpay, S. P. Vinh, N. Q. Priya, Shashank 2024-01-20T00:30:23Z 2024-01-20T00:30:23Z 2021-09-03 2017-10-18 2469-9950 https://pubs.kist.re.kr/handle/201004/122157 We report the dynamics of soft phonon modes and their role toward various structural transformations in Aurivillius materials by employing terahertz frequency-domain spectroscopy, atomic pair distribution function analysis, and first-principles calculations. We have chosen Bi4Ti3O12 as a model system and identified soft phonon modes associated with the paraelectric tetragonal to the ferroelectric monoclinic transition. Three soft phonon modes have been discovered that exhibit a strong temperature dependence. We have determined that the anharmonicity in Bi-O bonds plays a significant role in phonon softening, and that Bi cations play an important role in the emergence of ferroelectricity. English AMER PHYSICAL SOC TOTAL-ENERGY CALCULATIONS AUGMENTED-WAVE METHOD BISMUTH TITANATE DIELECTRIC-SPECTROSCOPY BASIS-SET BI4TI3O12 OXIDES Soft phonon mode dynamics in Aurivillius-type structures Article 10.1103/PhysRevB.96.134114 1 Physical Review B, v.96, no.13 Physical Review B 96 13 scie scopus 000413166600002 2-s2.0-85037135948 Materials Science, Multidisciplinary Physics, Applied Physics, Condensed Matter Materials Science Physics Article TOTAL-ENERGY CALCULATIONS AUGMENTED-WAVE METHOD BISMUTH TITANATE DIELECTRIC-SPECTROSCOPY BASIS-SET BI4TI3O12 OXIDES