Influence of individual phases and temperature on properties of CoFe2O4-BaTiO3 magnetoelectric core-shell nanocomposites

Magnetoelectric core-shell nanocomposites have tremendous applications in biomedical sectors such as targeted and controlled drug delivery for cancer treatment and non-invasive brain stimulation for treatment of Parkinson's disease. The neural activity deep in the brain is triggered with the help of these magnetoelectric nanocomposites by externally applied magnetic fields, since these materials exhibit substantial magneto-mechano-electrical coupling. Also, they posses better connectivity between the ferroelectric and ferromagnetic phases without interface effects. BaTiO3 (BTO) and CoFe2O4 (CFO) exhibits significant ferroelectric and ferromagnetic properties which are able to induce effective multiferroic properties. Core-shell nanocomposites of CoFe2O4 as core and BaTiO3 as shell, were synthesized by co-precipitation and sol-gel techniques, respectively. The optimum calcination temperature required to get pure BaTiO3 phase was observed to be 900 degrees C. The tetragonal phase of pure BaTiO3 and the spinal perovskite structure of pure CoFe2O4 was in accordance with the X-ray diffraction patterns. The core-shell type morphology of the synthesized nanocomposites were corroborated using Transmission Electron Microscopic images. The piezoelectric and magnetization response of these magnetoelectric nanocomposites were captured as functions of temperature and volume fractions of individual phases.