Magnetoelectric coupling of manganese ferrite–potassium niobate lead-free composite ceramics synthesized by solid state reaction method

Abstract

Lead-free composite ceramics xMnFe2O4-(1\u2009−\u2009x) KNbO3 with the composition of x\u2009=\u20090.20, 0.30 and 0.40 were synthesized by the solid state reaction method to obtain the composites of ferrite and ferroelectric to achieve magnetoelectric coupling. A confirmation study for the formation of spinel cubic MnFe2O4 ferrite ceramic and orthorhombic KNbO3 ferroelectric ceramic was performed by X ray diffraction. The strain in the composite for various compositions was estimated using W–H method to understand the variation of multiferroic features of the ceramic composites. The Transmission Electron Micrograph and High Resolution Transmission Electron Micrograph images reveal the existence of ferrite and ferroelectric phases. Weak magnetic behavior is exhibited by the ferrite-ferroelectric composites as compared to ferrite MnFe2O4. The 20:80 composite possesses the highest magnetic parameters among the compositions. The 40:60 composite recorded the maximum Pr and Ec values. The enhanced ME coupling between magnetic and ferroelectric phases is shown for 40:60 composite and the same is good for the lead free multifunctional device. All the composite samples show low current leakage.