La掺杂SrBi4Ti4O15铁电材料性能研究

按x=0.00，0.10，0.25，0.50，0.75和1.00，采用固相烧结工艺，制备了不同La掺杂量的SrBi_4-xLa_xTi₄O₁₅的陶瓷样品. 用x射线衍射对其微结构进行了分析，并测量了铁电、介电性能.结果发现，La掺杂未改变SrBi₄Ti ₄O₁₅的晶体结构.随掺杂量的增加，样品的矫顽场(E_c)下降，剩余极化(2P_{关键词： 4-x}La_xTi₄O₁₅')" href="#">SrBi_4-xLa_xTi₄O₁₅ La掺杂 铁电性能 相变温度 弛豫铁电

Study of properties of lanthanum doped SrBi4Ti4O15 ferroelectric ceramics

Ceramic samples SrBi_4-xLa_xTi₄O₁₅ (x =0.00, 0.10, 0.25, 0.50, 0.75, 1.00), have been prepared by solid-state reaction method. T heir structure was analyzed by x-ray diffraction, and their dielectricity and fe rroelectricity were measured. It is found that La-doping does not change the cry stal structure of SrBi₄Ti₄O₁₅. The remnant pola rization (2P₄) in creases at first, then decreases with the increase of La content. The 2P_{4 reaches a maximum value of 24.2 μC·cm^-2, when x is 0.25. The c oerc ive field of SrBi3.75La0.25Ti4O15 is 60.8 kV·cm^-1 . The 2P4 increases by about 50% and the Ec decrease s near 25%, compa red with these of SrBi4Ti4O15. Obviously, the f erroelectricity of SrBi 4Ti4O15 is improved by lanthanum doping. The te mperature of p hase transition (Tc) decreased with La cloping. The Tc of SrBi3.75La0.25Ti4O15 is 451 ℃. When x=0.75 and 1.00, the SrBi4-xLaxTi4O15 exhibit the typical characteristics of relaxor ferro electrics.}