Giant M-E effect of multiferroic BaTiO3--LaMnO3 ceramic composites

The magnetic and dielectric properties of ceramic composites, in which 10 mol% antiferromagnetic LaMnO₃ was added to ferroelectric BaTiO₃, have been investigated. X-ray diffraction measurement showed that ceramics sintered in the range of 1050-1150°C are composites containing a small amount of (La, Ba)MnO₃ phase along with BaTiO₃ phase. These composites were found to be multiferroic materials simultaneously exhibiting ferromagnetic and ferroelectric properties at room temperature. When an electric field of 2.3 kV/mm was applied to the composite sintered at 1200°C, a reduction of spontaneous magnetization as large as 70% was observed at room temperature. This reduction may be ascribed to the decrease of electron transfer interaction of the precipitated ferromagnetic (La, Ba)MnO₃ caused by electrostriction of the surrounding BaTiO₃ matrix.