Abstract:

Chromiun doped BaTiO₃ was synthesized with sol-gel technique. The Cr-doped BaTiO₃ was still in the structure of tetragonal perovskite by X-ray diffraction, and its transformation point of ferroelectric to paraelectric as well as the latent heat of the transformation were observed a little less than those of pure BaTiO₃, respectively, by the tests of differential scanning calorimetry. Layered composites Tb_1-xDy_xFe_2-y and BaTi_1-zCr_zO_3-δ were fabricated by bonding the discs of the doped BaTiO₃ and rare earth alloy Tb_1-xDy_xFe_2-y. The magnetoelectric (ME) effect of the layered samples was investigated. The transverse ME voltage coefficient for the bilayer Tb_1-xDy_xFe_2-y-BaTi_1-zCr_zO_3-δ and the trilayer Tb_1-xDy_xFe_2-y-BaTi_1-zCr_zO_3-δ-Tb_1-xDy_xFe_2-y reach 732.5 and 2753mV/A, respectively, under a bias magnetic field 28kA/m at room temperature, which are about 54% and 56% larger than those for the bilayer and trilayer composed by pure BaTiO₃, respectively. Since Cr-doped BaTiO₃ does not contain injurants, such as lead and zirconium, it can replace lead zirconium titanite as a “green” piezoelectric material for ME composites.

Key words: doped BaTiO₃, green piezoelectrics, magnetostrictive material, magnetoelectric effect