Preparation and Characterization of (1-x)BiFeO3- xNiFe2O4 (x=0, 0.3) Composite

Abstract

In the present work bismuth ferrite powder and nickel ferrite powder were successfully made by sol-gel method using bismuth ferrite pentahydrate [Bi(NO3)3.5H2O] and iron nitrate nonahydrate [Fe(NO3)3.9H2O]; and nickel nitrate hexahydrate [Ni(NO3)3.6H2O] and iron nitrate nonahydrate [Fe(NO3)3.9H2O] respectively as raw materials. The obtained powders were characterized by XRD which showed that besides the formation of single phase BiFeO3 an impurity phase was also observed. However, single phase NiFe2O4 were obtained. Composite structure of bismuth ferrite and nickel ferrite (0.7BiFeO3-0.3NiFe2O4) was made and its dielectric and ferroelectric properties were compared with pure BiFeO3. The dielectric properties studies showed that 0.7BiFeO3-0.3NiFe2O4 has smaller dielectric constant value and showed more dielectric losses as compared to pure BiFeO3. The dielectric constant value at room temperature for the composite was found to be 6.02 as compared to 29.51 for pure bismuth ferrite at 102 Hz. The ferroelectric studies at room temperature showed a hysteresis loop for pure bismuth ferrite with remnant polarization of 5.46μC/cm2 at coercive field of 2.48kV/cm for BiFeO3 as compared to asymmetrical oval shaped hysteresis loop for 0.7BiFeO3-0.3NiFe2O4 composite with remnant polarisation of 0.07μC/cm2 at coercive field of 16.96kV/