Magnetic and dielectric properties of Ca2+ doped Bi0.9La0.1FeO3 nanoparticles prepared by the sol-gel method

36-42Bi0.9-xLa0.1CaxFeO3 (x=0.05~0.25) nanoparticles were synthesized by an improved sol-gel technique. With an increasing x value, the grain size exhibits an initial drop followed by a subsequent rise. The temperature has a strong effect on the morphology of samples. This implies that 700℃ is the optimal temperature for the growth of crystals in the samples. The magnetization increases with an increase in the concentration of Ca2+ ions, and the doped crystals exhibit important features of anti-ferromagnetic spin ordering. The remanent magnetization (Mr) exhibits an initial reduction with a subsequent increase versus concentration (x) of Ca2+ ions, its minimal value corresponding to x=0.2. The substitution of Bi3+ ions by Ca2+ ions results in the change of the Fe3+-O-Fe3+ bond angle, accompanied by a distortion of the oxygen octahedra. With an increase in frequency, multiple Debye peaks appear in all samples, which indicate that the material possesses multiple-frequency energy absorption characteristics. Thus, the frequency-dielectric loss curve is characterized by the superposition of multiple Debye peaks