Tb_(1-x)Dy_xFe_(2-y)-BaTi_(0.99)Cr_(0.01)O_(3-δ)多层复合结构中的磁电效应

Magnetoelectric Effect in Laminate Composites Tb_(1-x)Dy_xFe_(2-y)-BaTi_(0.99)Cr_(0.01)O_(3-δ)

采用溶胶-凝胶法制备了Cr掺杂BaTiO3陶瓷片.X射线衍射显示Cr掺杂BaTiO3依然为四方相钙钛矿结构.差热分析显示,Cr掺杂BaTiO3的居里温度及相变潜热均比纯净BaTiO3的同类参量略低.将所得BaTi0.99Cr0.01O3-δ陶瓷片与Tb1-xDyxFe2-y粘结成磁电双层及三层复合结构材料.研究了双层Tb1-xDyxFe2-y-BaTi0.99Cr0.01O3-δ和三层Tb1-xDyxFe2-y-BaTi0.99Cr0.01O3-δ-Tb1-xDyxFe2-y复合材料的磁电效应.在28 kA/m的磁场下,两者的横向ME电压系数均达其峰值,为732.5和2753mV/A.该两数值分别是采用BaTiO3制备的同类双层及三层复合结构的同类数值的1.54及1.56倍.由于掺杂钛酸钡不含铅、锆等有害物质,因此采用掺杂BaTiO3替代锆钛酸铅做为"绿色"压电材料制备磁电效应器件具有研究和应用价值.

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 Tb1-x DyxFe2-y and BaTi1-xCr2O3-δ were fabricated by bonding the discs of the doped BaTiO3 and rare earth alloy Tb1-xDyxFe2-y, The magnetoelectric （ME） effect of the layered samples was investigated. The transverse ME voltage coefficient for the bilayer Tb1-x DyxFe2-y-BaTi1-z Cr2O3-δ and the trilayer Tb1-x DyxFe2-y·BaTi1-z Cr2O3-δ·Tb1-x DyxFe2-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.