A rapid route to perovskites: barium titanate nanoparticles via microwave-assisted solvothermal synthesis

Barium titanate (BaTiO₃) is a perovskite material with remarkable dielectric, ferroelectric, and piezoelectric properties, making it valuable in biomedical and functional devices. Its performance depends on the crystal structure, phase purity, and particle size. Conventional synthesis methods are energy-intensive and less scalable. Microwave-assisted solvothermal synthesis provides a more efficient and scalable alternative, enabling better control over particle characteristics. In this work, BaTiO₃ nanoparticles (BTNPs) were prepared using the microwave-assisted solvothermal approach to examine how the reaction time affects their structural and functional behaviour. Detailed characterization revealed that the sample synthesized within 30 minutes achieved the highest crystallinity and the lowest defect density. This sample also exhibited fewer surface-bound organic residues, mainly oxygen-bound metal precursors, compared to other samples. Morphological analysis revealed that the 30 minute synthesis yielded smaller, well-crystallized particles, whereas extending the reaction time led to agglomeration. These observations were further supported by surface potential measurements, which indicated improved colloidal stability. Overall, 30 minutes was identified as the optimal synthesis time, producing BTNPs with superior crystallinity, phase purity, and functional properties. This study underscores the microwave-assisted solvothermal approach as a rapid, energy-efficient, and scalable method to produce high-quality BTNPs for applications in the dielectric, optoelectronic, and biomedical fields.