Eu3+掺杂的铌酸钠钾陶瓷的制备及性能研究

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T_c=426℃。

Synthesis and Properties of Eu3+ Doped Potassium-sodium Niobate

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 T_c is 426℃.