Investigation of dielectric and magnetic nature of Bi7Fe3Ti3O21

Ceramic samples of Bi7Fe3Ti3O21 were prepared by a solid-state sintering route. X-ray diffraction showed that the material is single phase and isostructural with other bismuth layer structured ferroelectrics (BLSFs). Dc conductivity measured from room temperature to 640°C showed two slope changes. Dielectric measurements carried out in the temperature range 30–850°C indicated dielectric anomalies at 645 and 820°C. A pyroelectric signal was also measured and the coefficient evaluated. Magnetization measurements indicated that the material is antiferromagnetic in the temperature range 80–300 K, with a small hysteresis at room temperature. The properties are compared with other isostructural compounds.