Effect of Fe₂O₃ Doping on Phase Formation, Microstructure, Dielectric and Magnetic Properties of BNT-BKT-KNN Ceramics Prepared by the Solid-State Combustion Technique

Abstract

Lead-free 0.81(Bi_0.5Na_0.5TiO₃)-0.18(Bi_0.5K_0.5TiO₃)-0.01(K_0.5Na_0.5NbO₃) (BNT-BKT-KNN) ceramics doped with Fe₂O₃ (0–0.8 wt%), were prepared via the solid-state combustion method using glycine as fuel. The effect of Fe₂O₃ doping on the phase formation, microstructure, dielectric and magnetic properties of the ceramics was investigated. The XRD and Raman spectra of all ceramics indicated a pure perovskite structure with coexisting rhombohedral and tetragonal phases. The microstructure showed a polygon grain shape for all compositions. The average grain size and density of the ceramics tended to increase from 0.38 to 0.77 μm and 5.56 to 5.80 g/cm³ with increasing x content. The ceramics with 0.4 wt% Fe₂O₃ doping showed the highest maximum dielectric constant (ε_m=5424) which corresponded to the microstructure and density results. Without Fe₂O₃ doping, the BNT-BKT-KNN ceramic showed diamagnetic behavior, whereas all of the Fe₂O₃ doped ceramics exhibited paramagnetic behavior, measured at a temperature of 25^°C.

KEYWORDS:

• BNT-BKT-KNN
• perovskite
• solid-state combustion
• dielectric properties
• magnetic properties

Acknowledgments

The authors wish to thank the Department of Physics, Faculty of Science, Naresuan University for their supporting facilities. Thanks are also given to Asst. Prof. Dr. Kyle V. Lopin for his help in editing the manuscript.

Additional information

Funding

This work was supported by The National Science, Research and Innovation Fund (NSRF) through Naresuan University (R2564B001).