Sintering and characterization of SrBi2Ta2O9 obtained by high-pressure processing at low temperatures

• The first production of SrBi2Ta2O9 using the technique of high-pressure processing.
• The ability to produce single-phase SrBi2Ta2O9 treated at 2.5 GPa and 900 °C.
• The electrical properties are compatible with SBT sintered at high temperatures.

High-pressure processing is a very attractive approach for the production of materials with new and/or improved properties. In this work, pressures in the order of 7.7 GPa and 2.5 GPa were induced in SrBi2Ta2O9 samples at different temperatures placed in a specific reaction cell and generated different effects on phase formation. The microstructural evolution during high-pressure processing was investigated by scanning electron microscopy in association with energy dispersion spectroscopy and with the support of an X-ray diffraction analyzer. Frequency response analysis was used to obtain the dielectric curves by electrochemical impedance spectroscopy. A SrBi2Ta2O9 single-phase sample, treated at 2.5 GPa and 900 °C, was used to evaluate the electrical properties, obtaining a dielectric response similar to SrBi2Ta2O9 samples sintered by conventional processes at temperatures above 1000 °C. In addition, by this method, it was possible to obtain ceramics with uniform microstructure and a relative density of 93%.

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