Magnetodielectric effect in rare earth doped BaTiO3-CoFe2O4 multiferroic composites

An effective strategy for the development of multiferroic composite nanostructures with enhanced magnetoelectric coupling performance: a perovskite–spinel approach

“…Hence, the dielectric constant reduces and becomes independent of the frequency in the high frequency region. 33,42 The value of the dielectric constant increases as the concentration of NFO increases in the composites.…”

“…This results in an increase in the dislocation density, which enhances the strain between the BFO and NFO phases, thereby improving the ME effect in the composites. 33 …”

“…It confirms that most of the spins are directed away from the preferred magnetic field, which results in stress and hence the remanent magnetization increases. 33 The decrease in the coercivity ( H c ) can be attributed to its particle size. Herein, the decrease in the particle size with increasing NFO concentration in the composites contributes to a decrease in the coercivity.…”

“…The crystallite size is reduced because of the lattice distortion caused by the ionic radius difference 32 between Bi 3+ (1.17 A 0 ) and Ni 2+ (0.72 A 0 ). This results an increase in dislocation density which enhances the strain between BFO and NFO phases, thereby improves ME effect in the composites 33 .…”

“…It reduces the participation of charge carriers in hopping conduction mechanism. As the frequency of applied field increases, the charge carriers acquire certain amount of energy to break the grain boundaries and enter the grain segment 33 .…”