Intrinsic study for magnetoelectric coupling in nanoparticles

Intrinsic magnetoelectric (ME) coupling due to anomal phase transition temperature of multiferroic Pb1−xSrx(Fe0.012Ti0.988)O3 (PSFT) has been studied. The average particle size of PSFT specimens was measured from X-ray diffraction peaks and scanning electron microscopy. The ferromagnetic phase transition temperature ( T p m ) was evaluated by temperature dependent heat flow, initial permeability ( μ i ) and magnetic susceptibility ( χ ) . However, ferroelectric phase transition temperature ( T p e ) was observed from temperature dependent relative permittivity ( ε ) , and dc resistivity ( ρ d c ) . The doping of Fe in PbTiO3 (PSFT0) has greatly reduced T p e , while the doping of Sr in PSFT0 has reduced T p m . The higher frequency dependent dielectric constant is explained in terms of higher dc resistivity of the PSFT nanoparticles involving Variable-Range-Hopping (VRH) conduction. The observed VRH mechanism shows low value of activation energy (i.e., in the order of meV) of fermi gap giving large ME output.