Investigation of structural, magnetic, and dielectric properties of Bi_{1− x} Ca _x Fe_{1− y} Ni _y O₃ multi-ferroic prepared via a facile microwave-assisted method

In this work, the bismuth ferrite Bi_{1− x} Ca _x Fe_{1− y} Ni _y O₃ ( x   =  0, y   =  0 and x   =  0.05, y   =  0 and x   =  0.05, y   =  0.05 and x   =  0, y   =  0.05) nanopowders were prepared using the microwave irradiation technique, and the effect of doping on the structural, magnetic, and dielectric properties was studied. This structural study showed that all samples had a rhombohedra structure phase with the space group R3c. The results obtained from the FESEM images and XRD show that the crystallite and particle sizes decrease by Ca and Ni doping. Magnetic measurements confirmed the anti-ferromagnetic majority phase for the BiFeO₃ and Bi_0.95Ca_0.05FeO₃ samples, and the ferromagnetic phase for the BiFe_0.95Ni_0.05O₃ and Bi_0.95Ca_0.05Fe_0.95Ni_0.05O₃ samples. The results obtained from the dielectric constant and dielectric loss indicated that the BiFeO₃ sample had the lowest and the Bi_0.95Ca_0.05FeO₃ sample had the largest values for dielectric constant and dielectric loss in the entire measured frequency range. (paper)