Structure and magnetic properties of the Co1-xNixFe2O4-BaTiO3 core-shell nanoparticles

Core-shell Co1-xNixFe2O4-BaTiO3 (0 ≤ x ≤ 1) composite nanoparticles were synthetized by a combination of soft chemical routes such as co-precipitation and sol gel. X-ray diffraction patterns confirm the presence of both the materials, the ferrite solid solution, and BaTiO3. Unit cell parameters become smaller as Ni concentration is increased. SEM and HRTEM micrographs corroborate the formation of core-shell nanostructures. Magnetic behaviors of the core are very different from those of the composites. Anomalous magnetic behavior of the composite nanostructures have been discussed considering a coupling between the ferromagnetic and ferroelectric phases. Present work provides an experimental evidence of complex behaviors in magnetoelectric composites and strengthens the idea of remarkable changes of the magnetoelectric properties depending on the nanostructures, morphology or the method of synthesis.