Ceramics have been prepared by sol-gel technique. X-ray diffraction data indicated a phase transition from rhombohedra with space group R3c toorthorhombic structure and decreasing in crystallite size from26.27nm to 21.05nm for x=0.1, 0.15, respectively. The activation energy for electrical conduction has been calculated from the Arrhenius plot using impedance measurement. The activation energy for the grain conduction was found to be increased from 0.286 eV to 0.38eV for x=0.1, 0.15, respectively measured in the temperature ranges (. The vibrating sample magnetometer (VSM)results showed that the saturation magnetization (Ms) increased from 13.24emu/g for x=0.1 to 39.59 emu/g for x=0.15, due to the collapse of spin cycloid structure. The remnant magnetization (Mr) is also correspondingly enhanced from 3.43 emu/g to 11.88emu/g.

Ceramics of. . (x=0.1, 0.2) have been successfully synthesized by sol-gel technique. The Reitveld refinement XRD data indicated that the rhombohedra pure BFO is transformed to orthorhombic structure with the incorporation of Ho and Co co-doped in BFO ceramic. The increase in the co-substitution content resulted in the decreasing of crystallite size from 26 nm to 15 nm. The results have also revealed that the decrease in crystal parameters, tolerance factor and porosity. The dielectric measurements have shown that with increasing co-doping contents the dielectric constant is enhanced in the lower frequency region and abruptly decreased with frequency and tend to attain constant at higher frequency region. Both the dielectric constant and dielectric loss are increased with temperature up to a transition temperature called Neel temperature, which reveal the magneto-electric coupling. Increasing the co-doping content yields in enhancing spontaneous magnetization from 5.046 emu/g to 17.75 emu/g. The remnant magnetization also enhanced from 0.966 emu/g to 5.55 emu/g with increasing of x from 0.1 to 0.2, respectively.