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Updated: Feb 10, 2026

High Pressure Single Crystal Diffraction at PX^2
Published on: January 16, 2017
Polymorphism of BaTeO3 under High Pressure: Single-Crystal Structure Analysis and Characterization of HP-BaTeO3
Benjamin J Pullicino1, Stefan Schwarzmüller1, Gunter Heymann1
1Institut für Allgemeine, Anorganische und Theoretische Chemie, Universität Innsbruck, Innrain 80-82, Innsbruck A-6020, Austria.
None:
A new high-pressure polymorph of barium tellurate, HP-BaTeO3, was synthesized using multianvil high-pressure/high-temperature techniques (4 GPa, 900 °C). The compound crystallizes in the monoclinic space group P21/c and consists of stacked trigonal pyramidal [TeO3]2- units interconnected by secondary bonds. Structural analysis identifies significant differences between HP-BaTeO3 and its ambient-pressure polymorph, BaTeO3(I), including a doubling of the c-axis and additional secondary bonding within the bc plane. The optical properties of HP-BaTeO3 were investigated using ultraviolet-visible spectroscopy, revealing a widened bandgap compared to BaTeO3(I), attributed to changes in orbital overlap and lone pair orientation. Thermal analysis and high-temperature powder X-ray diffraction confirmed the metastable nature of HP-BaTeO3, with a phase transition to BaTeO3(I) occurring at approximately 550 °C. This study highlights the structural and electronic modifications induced by high-pressure synthesis and provides insights into the relationship between the two polymorphs.
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