采用固相烧结法制备了Eu3+掺杂的铌酸钠钾(KNN)陶瓷。用X射线粉末衍射仪、荧光光谱测试仪和LCR精确阻抗测试仪等对其结构、发光性能和介电性能进行表征。XRD结果显示样品为钙钛矿结构。荧光分析结果表明, 致密度对KNN陶瓷材料发光性能有一定的影响, Eu3+掺杂量是影响其发光性能的重要因素。其中掺杂Eu摩尔分数为4%的样品在930 ℃焙烧后其发光最强, 在396 nm紫外光激发下, 发射光谱最强峰在614 nm, 对应于Eu3+的5D0-7F2电偶极跃迁。样品经3 kV/cm、110 ℃极化30 min后进行压电性能检测, 结果表明提高Eu3+掺杂量以及陶瓷的致密度, 可改善压电性能。其中掺杂4%Eu的KNN压电常数D33最大为98 pC/N, 在1 kHz、100 ℃时, 介电常数最小为217, 介电损耗tanθ=0.199, 且仍然保持较高的居里温度Tc=426 ℃。

Eu3+ doped potassium-sodium niobate(KNN) ceramics were fabricated by a solid-state reaction method. X-ray diffraction, photoluminescence spectra and LCR meter were used to characterize the structure and properties of Eu3+ doped KNN ceramics. XRD results show that the obtained KNN ceramics are orthogonal architecture. The relative density and Eu3+doping concentration can affect the luminescent properties of KNN ceramics, Eu3+doping mole fraction is a key factor. 4% Eu3+ doped KNN ceramics at 930 ℃ sintering temperature has excellent red-orange luminescence under 396 nm excitation, and the strongest emission peak is located at 614 nm, corresponding to 5D0-7F2 transition of Eu3+. The piezoelectric properties of all samples are measured after polarized at 3 kV/cm and 110 ℃ for 30 min. The results reveal that the piezoelectric properties can be improved by increasing the Eu3+ content and the ceramics relative density. KNN-4%Eu3+ceramics shows good piezoelectric and dielectric performance. Piezoelectric constant D33 reaches up to 98 pC/N, dielectric constant ε is 217, dielectric loss tanθ is 0.199(1 kHz, 100 ℃) and Curie temperature Tc is 426 ℃.