Soaking time effect on the properties of perovskite structure bismuth ferrite

Abstract

Bismuth ferrite with chemical formula BiFeO₃ was synthesized using the sol–gel method. The synthesized powder in three proportions was given sintering at 600 °C in a conventional furnace with soaking time of 1 h, 3 h and 5 h each. XRD technique was used to check the formation of phases for all the samples. From the XRD data, the lattice constants and the theoretical densities were calculated using Match! Software. Fourier transform Infrared spectroscopy was used for confirming the formation of Bi–O and Fe–O bonds. The crystallite sizes were calculated using Debye Scherrer’s formula. Dielectric constant of the samples was studied as a function of soaking time and frequency of the applied electric field. Dielectric constant was found to decrease with increasing soaking time. Dispersion with frequency was observed for the dielectric constants. P–E loop analysis was carried out, and variation of the maximum polarization and the coercivity with soaking time were analyzed. M–H loop was also measured, and parameters such as saturation magnetization and coercivity were studied. In M–H loop, the two parameters show increase up to 3 h soaking time and then later decrease. Possible mechanisms contributing to all the results obtained are being discussed.