Low-frequency magnetoelectric coupling of Tb_1-xDy_xFe_2-y-BaTi_0.99Mn_0.01O_3+δ layered composites

A elastic mechanics model was introduced to derive the magnetoelectric voltage coefficients of magnetostrictive-piezoelectric bilayer according to the constitutive equations. The transverse magnetoelectric coupling of Tb_1-xDy_xFe_2-y-BaTiO₃ layered composites were calculated by using the corresponding material parameters of individual phases. 1.0%(mole fraction) Mn doped BaTiO₃ (BaTi_0.99Mn_0.01O_3+δ) was synthesized with sol-gel technique. Layered composites were fabricated by binding discs of rare earth alloy Tb_1-xDy_xFe_2-y and Mn doped BaTiO₃, and the transverse magnetoelectric was investigated. XRD and DSC analysis show that Mn doped BaTiO₃ keeps the tetragonal structure at room temperature, and the phase transition temperature and the latent heat of ferroelectric to paraelectric are a little less than those of BaTiO₃. The peak values of transverse magnetoelectric voltage coefficients for Tb_1-xDy_xFe_2-y-BaTi_0.99Mn_0.01O_3+δ and Tb_1-xDy_xFe_2-y-BaTi_0.99Mn_0.01O_3+δ-Tb_1-xDy_xFe_2-y reach 529.4 mV/A and 1659.5 mV/A under a bias magnetic field of about 33 kA/m, which are 1.48 and 1.45 times of Tb_1-xDy_xFe_2-y-BaTiO₃ and Tb_1-xDy_xFe_2-y-BaTiO₃-Tb_1-xDy_xFe_2-y, respectively. The transverse magnetoelectric voltage coefficient of trilayer composites is about three times as large as those for bilayers of the same kind.