Dielectric properties of bismuth layer-structured ferroelectric Bi3R2Ti3FeO15 (R = Bi, Gd, and Nd) at microwave and radiofrequency (Jun, 10.1007/s10854-021-06332-4, 2021)

Bismuth layer structured ferroelectric Bi3R2Ti3FeO15 with R = Bi (BFTO), Gd (BGFTO), and Nd (BNFTO) composition were synthesized by solid-state route, and their morphology and dielectric properties were investigated. The BGFTO and BNFTO samples, show a decrease in dielectric characteristics compared to BFTO. This can be explained by structural distortion resulting from the replacement of lanthanides in the cations of A-site in the perovskite layer. Impedance spectroscopy was performed to establish a correlation between the electrical properties and the microstructure of the ceramics. A non-Debye relaxation induced by a thermally activated mechanism can be observed in all samples. The activation energy of the materials found in the range of 0.6–0.9 eV and indicates the association of doubly ionized oxygen vacancy. The three phases proved to be news candidates for X4D capacitors, with excellent temperature stability (29–150 °C, TCC ≤ ± 3.3%). In addition, the electroceramics were used to design a cylindrical dielectric resonator antenna (CDRA) for microwave applications. The Bi3R2Ti3FeO15-based CDRA showed great potential for microwave antenna application operating in the S-band. A change is observed to τf of BFTO phase (− 428.48 ppm °C−1) to BGFTO (+ 59.17 ppm °C−1) and BNFTO (+ 57.69 ppm °C−1). This result opens up a great opportunity for future work in CDRA with near-zero temperature coefficients (τf ∼ 0). © 2021, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.