Comparison between microwave and conventional calcination techniques in regard to reactivity and morphology of co-precipitated BaTiO3 powder, and the electrical and energy storage properties of the sintered samples

Abstract

Barium titanate (BaTiO3) nanopowders were synthesized by an aqueous co-precipitation method followed by calcination. Either 2.45GHz microwaves or conventional heating was used in order to investigate the impact of these techniques on the synthesis time, microstructure, and electrical properties of the materials. The heating temperatures ranged from 620°C to 810°C. X-ray diffraction (XRD) revealed pure BaTiO3 formation by microwave heating in a noticeably shorter time (five minutes) compared to conventional heating (3h). Field emission scanning electron microscopy (FESEM) results confirmed that the microwave process led to nanocube formation, whereas in the conventional procedure, the particles tended to form spherical shapes. To evaluate the electrical properties, the samples heated at 620°C were conventionally sintered at 1280°C, 1330°C, and 1380°C. Higher dielectric, piezoelectric, and ferroelectric properties and more energy-saving efficiency (εr=1012, tanδ=0.035 d33=85 pC/N, pr=6.2µC/cm2 and η=48% respectively) were achieved in the microwave-heated BaTiO3 sintered at 1380°C compared to the conventionally heated BaTiO3 (εr=824, tanδ=0.030 d33=75 pC/N, pr=5µC/cm2 and η=27%) demonstrating that microwave calcination substantially affects the final electrical properties.