Polymorphic phase transition in BaTiO3 by Ni doping. Issue 13 (September 2019)

• Record Type: Journal Article
• Authors: Duong, Nguyen Xuan; Bae, Jong-Seong; Jeon, Jongchul; Lim, So Yeon; Oh, Soo Han; Ullah, Aman; Sheeraz, Muhammad; San Choi, Jin; Ko, Jae-Hyeon; Yang, Sang Mo; Kim, Kyou-Hyun; Kim, Ill Won; Ahn, Chang Won; Kim, Tae Heon
• Is Part Of: Ceramics international. Volume 45:Issue 13(2019)
• Page Start: 16305
• Page End: 16310
• Publication Date: 2019-09
• Subjects: Structural phase transition -- BaTiO3 -- Oxygen vacancy -- X-ray photoelectron spectroscopy; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2019.05.156
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: We demonstrate a phase transition between BaTiO3 polymorphs induced by Ni substitution experimentally. The structural evolution of tetragonal-to-hexagonal polymorph in Ni-doped BaTiO3 ceramics is observed macroscopically and then, visualized in an atomic scale. Under this structural transition, the long-range ferroelectric ordering in the undoped BaTiO3 with tetragonal symmetry is suppressed and eventually, vanishes in the heavily Ni-doped BaTiO3 with hexagonal symmetry and dielectricity. An oxygen vacancy defect can be created at a local Ni doping site with a decrease in the charge valence state from Ti 4+ (3 d 0 ) to Ti 3+ (3 d 1 ). With the reduction of the Ti 4+ oxidation state, the polar Ti–O ionic displacement is degenerated in the tetragonal BaTiO3 and thereby, the short-range Coulomb repulsion may be restored in the hexagonal BaTiO3 resulting in a polymorphic phase transition. Our work is of potential interest for artificial realization of an exotic phase in complex oxide materials by doping.