Magnetic and magnetoelectric response of Gd doped nickel ferrite and barium titanate nanocomposites

Composites of NiFe2O4 (NFO)-BaTiO3 (BTO) and NiGd0.01Fe1.99O4 (G0.01)-BTO were investigated by x-ray diffraction, magnetization, transmission electron microscopy, magnetocapacitance, and ferroelectric studies. NFO and G0.01 nanoparticles were synthesized by the sol-gel method. The crystallite size of the nanoparticles estimated from the x-ray diffraction patterns is 20-22nm. The average crystallite sizes of NFO and G0.01 nanoparticles were estimated from the transmission electron micrographs as 26 (1) nm and 22.3 (0.3) nm, respectively. These nanoparticles were encapsulated in a BTO shell, resulting in the formation of nanocomposites. Room temperature magnetization (at 60kOe) of G0.01 nanoparticles was found to be slightly higher than that of NFO nanoparticles, due to the larger moment of Gd3+ than that of Fe3+. Also, the magnetization of G0.01-BTO is more than that of NFO-BTO nanocomposites. The magnetoelectric effect was observed with a magnetocapacitance value of approximately -10% at 10kHz in both the composites. Published under license by AIP Publishing.