Magnetoelectric Effect in Ceramics Based on Bismuth Ferrite

Solid-state sintering method was used to prepare ceramic materials based on bismuth ferrite, i.e., (BiFeO 3 ) 1 − x –(BaTiO 3 ) x and Bi 1 − x Nd x FeO 3 solid solutions and the Aurivillius Bi 5 Ti 3 FeO 15 compound. The structure of the materials was examined using X-ray diffraction, and the Rietveld method was applied to phase analysis and structure refinement. Magnetoelectric coupling was registered in all the materials using dynamic lock-in technique. The highest value of magnetoelectric coupling coefficient α ME was obtained for the Bi 5 Ti 3 FeO 15 compound ( α ME ~ 10 mVcm −1 Oe −1 ). In the case of (BiFeO 3 ) 1 − x –(BaTiO 3 ) x and Bi 1 − x Nd x FeO 3 solid solutions, the maximum α ME is of the order of 1 and 2.7 mVcm −1 Oe −1 , respectively. The magnitude of magnetoelectric coupling is accompanied with structural transformation in the studied solid solutions. The relatively high magnetoelectric effect in the Aurivillius Bi 5 Ti 3 FeO 15 compound is surprising, especially since the material is paramagnetic at room temperature. When the materials were subjected to a preliminary electrical poling, the magnitude of the magnetoelectric coupling increased 2–3 times.