The bismuth orthotantalate with high anisotropic thermal expansion. (December 2019)

• Record Type: Journal Article
• Authors: Zhuk, N.A.; Krzhizhanovskaya, M.G.; Belyy, V.A.; Sekushin, N.A.; Chichineva, A.I.
• Is Part Of: Scripta materialia. Number 173(2019)
• Page Start: 6
• Page End: 10
• Publication Date: 2019-12
• Subjects: Phase transformations -- Thermal expansion -- X-ray diffraction (XRD) -- Differential scanning calorimetry (DSC); Materials -- Periodicals; Metallurgy -- Periodicals; Metalen; Legeringen; Materiaalkunde; Metals, metalworking and machinery industries; Metals; Electronic journals; 620.11
• DOI: 10.1016/j.scriptamat.2019.07.039
• Languages: English
• ISSNs: 1359-6462

Abstract

Abstract: The triclinic phase of the bismuth orthotantalate (β-BiTaO4 ) exhibited strong anisotropy of thermal expansion in the temperature range of 25–750 °C. The character of the thermal expansion of β-BiTaO4 changed radically near 200 °C, which was not observed in its isomorphic analog (β-BiNbO4 ). In the same temperature range the electrical properties also exhibited the local extremum. Crystal structure of β-BiNbO4 was refined at 25, 200, 400 and 600 °C from powder X-ray diffraction data. The role of bismuth lone-electron pair is discussed. β-BiTaO4 has a potential to be used as a thermal expansion material. Graphical abstract: Unlabelled Image