Enhancement in magnetic, piezoelectric and ferroelectric properties on substitution of titanium by iron in barium calcium titanate ceramics

Lead free polycrystalline ceramics with compositional formula Ba0.90Ca0.10Ti1–3x/4FexO3 (BCT), (x=0.000, 0.005, 0.010, 0.015 and 0.020) were prepared by the solid state reaction method. The effect of substitution of Fe3+ ion at Ti-site on the ferroelectric and piezoelectric properties of BCT ceramics was studied. Remanant polarisation (Pr) and saturation polarisation (Ps) show an increasing trend while the reverse trend was observed for coercive field (Ec) with Fe3+ substitution. The values of the piezoelectric charge coefficient (d33) and piezoelectric coupling coefficient (kp) was found to increase with increase in Fe content. Ceramic sample with x=0.02 was found to have a maximum value of d33 (130 pC/N) and kp (29%). The prepared ceramic samples show magnetic properties as confirmed by recorded MH loops. On substitution of Fe3+ ions, the ferroelectric BCT ceramics show clear transformation of the diamagnetic nature of BCT ceramics to weak ferromagnetism.