Structure, morphology and magnetodielectric investigations of BaTi1-xFexO3- ceramics

Ferromagnetism is successfully imposed on a robust ferroelectric material by Fe-substitution and magnetodielectric investigation of the ceramics leads us to propose a sensor for magnetic field measurement. Tetragonal to hexagonal structural phase transformation is unambiguously identified from Rietveld refinement of the structure. Coexistence of tetragonal and hexagonal phase is also identified from Raman spectra and SAED. Structural details of the two phases and phase percentage are correlated to the physical properties obtained from P-E loop, M-H loop and magnetodielectric measurements. Ferroelectric loops are diminished due to pinning of domain wall motion by oxygen vacancies and an increase of the non-ferroelectric hexagonal phase percentage. The decrease of remnant magnetization is ascribed to the occupancy of Fe in pentahedral-octahedral sites and oxygen vacancies. Magnetodielectric dispersion below 10(4) Hz is predominantly due to extrinsic origin through the combined effect of space charge polarization and magnetoresistance. The intrinsic magnetodielectric effect above 10(4) Hz is attributed to strain mediated magnetoelectric coupling.