|About this Abstract
||Materials Science & Technology 2019
||Phase Transformations in Ceramics: Science and Applications
||First-principles Investigation of Phonon Instabilities and Displacive Phase Transitions in CaTiO3-perovskites
||Venkateswara Manga, Thomas Zega, Krishna Muralidharan
|On-Site Speaker (Planned)
Phonons in crystals are central to many materials phenomena such as structural and magnetic phase transitions, thermal transport etc. Many of the studies aimed at designing new materials by tailoring structure and chemistry investigate the interplay between lattice vibrations and chemical effects within the crystals. To this end, first-principles density functional theory offers a powerful tool to study displacive phase transitions and the underlying phonon instabilities in ceramics. Specifically, the characterization of polyhedral distortions and their re-organizations in conjunction with the analysis of anomalous phonon softening/stiffening can reveal the mechanism of the phase transitions. Further, alloying elements by modifying the local atomic-binding and structure influence the phonon-instabilites and hence the phase transitions. In this talk, we shed light on the the effect of the alloying additions (such as Al, V etc.) on the displacive phase transitions in CaTiO3-preovskite while presenting the underlying thermodynamics and lattice vibrations in these ceramics.
||Definite: At-meeting proceedings