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Updated: Jun 1, 2025
Chemical Synthesis of Porous Barium Titanate Thin Film and Thermal Stabilization of Ferroelectric Phase by Porosity-Induced Strain
Published on: March 27, 2018
Dielectric properties depend on the crystal structure of perovskite-type RbTaO3 synthesized at high pressure
Kimitoshi Murase1, Jun-Ichi Yamaura2, Yousuke Hamasaki3
1Graduate School of Engineering and Science, Shibaura Institute of Technology, 307 Fukasaku, Minuma, Saitama, 337-8570, Japan. ayako@shibaura-it.ac.jp.
Abstract:
We successfully synthesized perovskite-type RbTaO3 at 1173 K under 4 GPa. RbTaO3 crystalized as a cubic system (Pm3̄m space group (SG), a = 4.04108(3) Å) at 300 K in contrast to the orthorhombic perovskite-type RbNbO3 prepared under the same conditions. During the cooling process, it reversibly transformed into a tetragonal phase (SG: P4mm) at 270 K, and into an orthorhombic phase (SG: Amm2) at 80 K. Corresponding to the phase transition, the relative permittivity showed a peak at 270 K with a maximum value of approximately 2000 and a kink at 80 K. This transition scheme is analogous to well-known displacement-type ferroelectrics of BaTiO3 and KNbO3. This is in contrast to KTaO3, which retains a cubic system and quantum paraelectric properties at the lowest temperature.
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