3. Results and Discussion The XRD patterns of calcined powders made from starting mixtures containing different levels of Bi2O3 and calcined with different heating rates are presented in Fig. 1. In case the heating rate of 10◦C/min, all powder samples showed a main phase of BFO. The analysis was carried out based on the JCPDS file No.86-1518. However, peaks of a second phaseat 2θ=28, 33 and 52◦were observed. This second phase was identified as Bi36Fe2O57according to the JCPDS file No. 42-0181. Further, a peak of Bi2O3at 2θ=56◦was alsoobserved. The formation of Bi36Fe2O57was also observed by Pradhanet al.[9] whileBi2Fe4O9and Bi36Fe2O57second phases were observed by Kimet al.who synthesized theBFO by sol-gel technique [7]. In the present work, it should be noted that intensity of theBi36Fe2O57peaks increased with increasing Bi2O3content for each heating rate. Plots ofvalue of intensity of the Bi36Fe2O57second phase (selected from peak at 2θ∼28◦)versusBi2O3content are displayed in insets of Fig. 1. Although the presence of free Bi2O3isexpected in the higher Bi2O3content samples, the results indicate that additive produce athree-phase mixture including BFO, Bi36Fe2O57and Bi2O3. In case a lower heating rate,the second phase disappeared especially for a smaller Bi2O3contented samples, as seenin Fig. 1(b) and (c). In case the heating rate of 1◦C/min, the pure phase of BFO wasobserved for the sample contained Bi2O3