Crystal Structure of Metastable Perovskite Bi(Mg1/2Ti1/2)O3: Bi-Based Structural Analogue of Antiferroelectric PbZrO3

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• 作者：Dmitry D. Khalyavin ; Andrei N. Salak ; Nikolai P. Vyshatko ; Augusto B. Lopes ; Nikolai M. Olekhnovich ; Anatoly V. Pushkarev ; Ivan I. Maroz ; Yury V. Radyush
• 刊名：Chemistry of Materials
• 出版年：2006
• 出版时间：October 17, 2006
• 年：2006
• 卷：18
• 期：21
• 页码：5104 - 5110
• 全文大小：295K
• 年卷期：v.18,no.21(October 17, 2006)
• ISSN：1520-5002

文摘

A metastable perovskite phase of Bi(Mg_1/2Ti_1/2)O₃ composition (BMT) has been obtained under high-pressure (6 GPa) and high-temperature (1270 K) conditions. X-ray and electron diffraction studies haverevealed a complex superstructure originating from antiferroelectric-like displacements of Bi³⁺ cationsand octahedral tilting. A group theoretical analysis was used to enumerate the possible crystal structurescompatible with both types of the distortions. On the basis of the symmetry arguments in combinationwith the diffraction methods, it has been concluded that the perovskite BMT is characterized by theorthorhombic Pnnm space group with unit cell parameters a = 11.3207(10) Å, b = 5.6433(10) Å, andc = 7.8314(10) Å. A relation of the BMT crystal structure to that commonly accepted for antiferroelectricperovskite PbZrO₃ (PZ) is discussed.