LAUSR

Lanthanum-doped cobalt nanoferrites CoLa X Fe 2− X O 4 ( X  = 0.00 to 0.08) were synthesized by using sol–gel method. A cubic spinel structure was confirmed by using X-ray diffraction pattern. A band obtained at 583 cm −1 recorded by Fourier transform infrared spectrum confirmed the presence of metal oxide spinel nanoferrites. The bandgap energy has increased with addition of La 3+ ions by using ultraviolet diffuse reflectance spectrum. The grain boundary contribution is greater than that of grain contribution due to small crystal size, which was confirmed by an impedance analysis. The dielectric constant and dielectric losses decreased with increasing frequencies. The binding energy of La, Co, Fe and O were determined by X-ray photoelectron spectroscopy. The magnetic studies were analyzed through vibrating sample magnetometer. The hysteresis loop revealed the soft ferromagnetic nature.