Structural, magnetic and dielectric properties of nano-crystalline Ni-doped BiFeO3 ceramics formulated by self-propagating high-temperature synthesis

Ni-doped BiFeO3 powders with the composition BiFe1-xNixO3 (x = 0.05, 0.1 and 0.15) were prepared by a self-propagating high-temperature synthesis (SHS), using metal nitrates as oxidizers and glycine as fuel. The X-ray diffraction (XRD) patterns depict that Ni-doped BiFeO3 ceramics crystallize in a rhombhohedral phase. The scanning electron micrographs of Ni-doped BiFeO3 ceramics show a dense morphology with interconnected structure. It is found that, the room-temperature magnetization measurements in Ni-incorporated BiFeO3 ceramics give rise to nonzero magnetization. The magnetization of Ni-doped BiFeO3 ceramics is significantly enhanced when Ni doping concentration reaches to x = 0.1 at 5 K. The variations of dielectric constant with temperature in BiFe0.95Ni0.05O3, BiFe0.9Ni0.1O3 and BiFe0.85Ni0.15O3 samples exhibit clear dielectric anomalies approximately around 450 degrees C, 425 degrees C and 410 degrees C respectively, which correspond to antiferromagnetic to paramagnetic phase transition of the parent compound BiFeO3.