Bi₄Ti₃O₁₂铁电薄膜的相变研究

Bi 4 Ti 3 O 12 铁电薄膜的相变研究 THE PHASE TRANSITION OF Bi 4 Ti 3 O 12 FERROELECTRIC FILM 周正国 Zhou Zhengguo 1 first-author 卢志红 Lu Zihong 1 李江鹏 Li Jiangpeng 1 章煜 Zhang Yu 1 黄良安 Huang Liangan 1 武汉大学物理学系,武汉,430072 武汉大学物理学系,武汉,430072 Department of Physics,Wuhan University . Department of Physics,Wuhan University . 用变温X射线及热分析等方法研究Bi 4 Ti 3 O 1 2铁电薄膜的相变,结果表明,在温度为350 4 45℃之间,薄膜经历由烧绿石相向钙钛矿相的结构相变,在670℃附近,薄膜由铁电相向顺电相转变;该相变是由于晶格畸变量b/a随温度上升连续减小,使得薄膜晶体对称性发生改变引起,在相变点附近未观察到潜热的产生。 Phase transition of Bi4Ti3O12（BTO） ferroelectric films were analyzed by x-ray diffraction and thermal analysis methods. The results indicate that the film transforms from the pyrochlore phase to the perovskite phase in the temperature range of 350-445℃ and transforms from the ferroelectric phase to the paraelectric phase at the 670℃. The ferro-para phase transition was brought about by continuous decrease of the orthorhombic distortion （ b/a ） which led the symmetry of the structure to be tetragonal. In the vicinity of phase transition point, no latent heat was observed. 铁电薄膜 相变 晶格畸变量 对称性 ferroelectric film phase transition orthorhombic distortion symmetry O484.4 国家自然科学基金资助的课题 1996-03-01 2021-04-01 3