(1-x)K_(0.5)Na_(0.5)NbO_3-xLiNbO_3∶Pr铁电陶瓷相变区光流明性能研究

Photoluminescence of (1-x)K_(0.5)Na_(0.5)NbO_3-xLiNbO_3∶Pr ferroelectric ceramics in phase transition area

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)K0.5Na0.5Nb O3-x Li Nb O3陶瓷.通过XRD相结构分析发现,随着Li Nb O3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.

0. 3 mol% Pr3 ＋-doped lead-free K0. 5Na0. 5Nb O3-x Li Nb O3 dense ceramics were synthesized via a conventional solid-state reaction method. With the increase of Li Nb O3 content,X-ray diffraction analysis indicated 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 photoluminescence 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 materials possessed advantages of noncontact and quick response.