（1－x）K0．5 Na0．5 NbO3－xLiNbO3∶Pr 铁电陶瓷相变区光流明性能研究

摘要

0.3 mol% Pr3+-doped lead-free K0.5 Na0.5 NbO3-xLiNbO3 dense ceramics were synthesized via a conventional solid-state reaction method.With the increase of LiNbO3 content, X-ray diffraction analysis indi-cated that the phase structure of the ceramics changed from orthorhombic to tetragonal at x=0.05.Increasing x from 0 to 0.10, the photoluminescence peak intensity of red emission at 603 nm and 650 nm firstly increased and then decreased, giving to the extreme value at x=0.05.The strong dependence of x on the photolumines-cence was attributed to the high hypersensitivity of Pr3+to the variation of lattice environment and symmetry. The photoluminescence indicating compositional changes and structure symmetry in ferroelectric ceramic mate-rials possessed advantages of noncontact and quick response.%采用传统的固相烧结法制备了摩尔百分比为0．3％ Pr3＋掺杂的（1－x） K0．5 Na0．5 NbO3－xLiNbO3陶瓷．通过XRD相结构分析发现，随着LiNbO3含量的增加，样品的晶格结构在x＝0．05时出现了由正交相到四方相的相变．当x由0增加至0．10时，位于603 nm 和650 nm 处的红光强度有先增加后减小的趋势，且在x＝0．05时获得最大值．理论分析表明，材料光流明强度在相变区的突变可能来自于Pr3＋对晶格参数及周围环境对称性变化的高度敏感性．本研究结果表明，光流明效应可以用来检测铁电材料的相变．该非接触式、响应快的新型检测铁电相变的方法具有很好的应用前景．