Dielectric and magnetic properties of (BiFeO3)(1-x)(PbTiO3)(x) ferromagnetoelectric system

摘要

BiFeO3-PbTiO3(BFPTO) ferromagnetoelectric (FME) material, with improved resistivity (similar to 10(9) Omega cm) and high relative density (similar to 0.95) is successfully prepared by sol-gel method. The microstructures, dielectric and magnetic properties are investigated by mean of X-rays diffraction, Scanning electron microscope, impedance analyzer and Vibrating sample magnetometer. A well crystalline powder was obtained after annealing in air at 825 degrees C for 20 min. The average particle size of sample calcined at 825 degrees C is 1-2 mu m. Structural transformation from rhombohedral (x = 0.0) to tetragonal (x = 0.3) has been revealed from XRD analysis. Dielectric constant and resistivity of BFPTO is found to be increase as the content of PbTiO3 (PTO) increase and tangent loss are reduced by increasing the content of PTO in BFPTO composites. The study of M-H curve reveals that BiFeO3 (BFO) is antiferromagnetic with small residual magnetism (0.012 emu/g) due to canting of the spin. For composites with x = 0.1 and 0.3, a large induced magnetization was observed than that of BiFeO3 single Crystal. Hence BFPTO prepared in study can be leads to ferromagnetic state that has remanent magnetization, unlike that of the earlier reported BiFeO3.