粉末冶金与采矿学报

抽象的

Chemical Synthesis and Structural Properties of Nd, Gd and Dy Doped BiFeO₃ Lead Free Ceramics

Kumar A and Varshney D*

The present study reports the structural aspects of BiFeO₃, Bi_0.9Ba_0.1Fe_0.9M_0.1O₃, (M=Co, Mn) and Bi0.80RE0.2FeO₃ (RE=Nd, Gd and Dy) powders as prepared by solid state reaction route while Bi_0.80Sr_0.2FeO₃ ceramic has been prepared using citrate sol-gel process. X-ray diffraction along with the Rietveld-refinement reveals the rhombohedral (R3c) structure for BiFeO₃ and Bi_0.9Ba_0.1Fe_0.9M_0.13, (M=Co, Mn), whereas, tetragonal (P4/mmm) for Bi_0.80Sr_0.2FeO₃ ceramic. In case of rare earth substitution there is an abrupt change in the crystal structure. Bi_0.8Nd_0.2FeO₃ ceramic crystallizes in triclinic structure (P1), Bi_0.8Gd_0.2FeO₃ compound shows a major contribution is related to orthorhombic (Pna21) symmetry and minor contributions are attributed to Pnma and R3c phase, whereas the X-ray diffraction of Bi_0.8Dy_0.2FeO₃ confirms the biphasic (Pnma+R3c) nature of the compound. All the properties of the ceramics reflect their structure so, structural evolution is important for enhancing the physical properties at room temperature.