Crystal structure of metastable perovskite Bi(Mg1/2Ti1/2)O-3: Bi-based structural analogue of antiferroelectric PbZrO3

authors	Khalyavin, DD; Salak, AN; Vyshatko, NP; Lopes, AB; Olekhnovich, NM; Pushkarev, AV; Maroz, II; Radyush, YV
nationality	International
journal	CHEMISTRY OF MATERIALS
keywords	MORPHOTROPIC PHASE-BOUNDARY; GROUP-THEORETICAL ANALYSIS; LEAD-FREE; PIEZOELECTRIC SYSTEM; SOLID-SOLUTION; TEMPERATURE; DIFFRACTION; CERAMICS
abstract	A metastable perovskite phase of Bi(Mg1/2Ti1/2)O-3 composition (BMT) has been obtained under high-pressure (6 GPa) and high-temperature (1270 K) conditions. X-ray and electron diffraction studies have revealed a complex superstructure originating from antiferroelectric-like displacements of Bi3+ cations and octahedral tilting. A group theoretical analysis was used to enumerate the possible crystal structures compatible with both types of the distortions. On the basis of the symmetry arguments in combination with the diffraction methods, it has been concluded that the perovskite BMT is characterized by the orthorhombic Pnnm space group with unit cell parameters a = 11.3207(10) angstrom, b = 5.6433(10) angstrom, and c = 7.8314(10) angstrom. A relation of the BMT crystal structure to that commonly accepted for antiferroelectric perovskite PbZrO3 (PZ) is discussed.
publisher	AMER CHEMICAL SOC
issn	0897-4756
year published	2006
volume	18
issue	21
beginning page	5104
ending page	5110
digital object identifier (doi)	10.1021/cm061129w
web of science category	Chemistry, Physical; Materials Science, Multidisciplinary
subject category	Chemistry; Materials Science
unique article identifier	WOS:000241106800020