Effect of Lanthanum Substitution on Magnetic and Structural Properties of Nickel Ferrite

Inverse spinel ferrites have demanded substantial attention in the recent past owing to their diverse technological deeds by conquering admirably with its surface, finite size effects and optical properties which has its proficient applications in photocatalytic degradation, magnetic resonance imaging and sensors etc. The substituted La3+ ions delay the development of grain growth of the materials in a meticulous manner compared with that of the pure Ni ferrites. We tale development of magnetic features in La3+ substituted Ni nano-ferrites synthesized by co-precipitation technique and then analyzed from the structural and magnetic perspectives. A credible and thriftily doable co-precipitation method has been the spotlight of forethought in recent decades to synthesize these ferrite nanoparticles. Enviable inverse spinel phase has been observed, as it is essential to modify and optimise its micro structural and magnetic features. The phase formation and significant properties of Ni1-xLaxFe2O4 ferrites were investigated using XRD, FTIR, TEM, UV-visible, VSM and FT-Raman techniques. The crystallite size of the as-synthesized nanoparticles were observed after the substitution of La3+ content in the range of 8 to 15 nm. As the dopant concentration increases the crytallite size increases and other changes in crystallographic parameters, as well as the cation distribution also observed. The TEM micrograph clearly reveals the cubic and the notable polycrystalline nature. The FTIR measurements carried out in the range of 400-4000 cm-1 elucidates the occurrence of functional groups. The UV-visible spectrum analysis reveals the optical property of as-synthesized nanoparticle and hence their band gap was found using Kubelka-Munk plot. The magnetic parameters were studied by vibrating sample magnetometer and the saturation magnetization of the ferrites at the room temperature decreases with the reduction in size.