HU B F, WEI H R, YANG Z W,et al.Optical transmittance， dielectric properties and impedance spectroscopy of （1-x）(K_0.5Na_0.5）NbO₃-xSr_0.7La_0.2ZrO₃ ceramics[J].Journal of Henan Polytechnic University(Natural Science) ,2026,45(3):179-187.

（1-x)(K_0.5Na_0.5）NbO₃-xSr_0.7La_0.2ZrO₃陶瓷的透光性、介电性能及阻抗谱研究

胡保付, 韦厚任, 杨再文, 刘丙国, 徐坚, 汪舰, 杜保立

河南理工大学 物理与电子信息学院，河南 焦作454003

摘要:目的 为探究（K_0.5Na_0.5）NbO₃-xSr_0.7La_0.2ZrO₃ （KNN-SLZ）陶瓷的透光性、电导机制和介电弛豫特性，开展（1-x）(K_0.5Na_0.5）NbO₃-xSr_0.7La_0.2ZrO₃陶瓷的透光性、介电性能和阻抗谱研究。  方法 采用固相法制备KNN-SLZ陶瓷，通过引入Sr_0.7La_0.2ZrO₃（SLZ）调控材料的微观结构。采用XRD，SEM表征陶瓷的结构形貌；利用紫外-可见-红外分光光度计和LCR分析仪测试陶瓷样品透光性和介电性能；利用阻抗分析仪测试样品的变温阻抗谱和电模量谱。  结果 结果表明，KNN-SLZ陶瓷为赝立方钙钛矿结构，陶瓷晶粒尺寸为［0.1，0.5］μm，陶瓷中分布有少量气孔。亚微米级的晶粒尺寸有利于提高陶瓷透光率。陶瓷的透光率随着SLZ掺杂含量的增加逐渐增大，在波长为2 000 nm红外区，透光率达到45％。测试频率为[10², 2×10⁶］ Hz时，陶瓷的介电常数高于2 050，介电损耗小于0.1，展现出良好的频率稳定性。高温阻抗谱分析表明，KNN-SLZ陶瓷中存在非德拜弛豫现象，陶瓷中的空间电荷主要为电离的氧空位，电离氧空位的短程跳跃在高温介电弛豫过程中发挥关键作用。在中高频区，温度对陶瓷电导的影响减弱，陶瓷的导电机制由低频时电荷的长程迁移转变为局域态之间的短程跃迁。  结论 优异的光电性能使KNN-SLZ陶瓷在透明性电学元件中应用前景广阔。

关键词:铌酸钾钠;无铅透明陶瓷;电性能;阻抗分析;介电常数

doi:10.16186/j.cnki.1673-9787.2024020028

基金项目:国家自然科学基金资助项目（51772076）； 河南省自然科学基金资助项目（182300410193）；河南省科技攻关项目（172102210278）

收稿日期:2024/02/28

修回日期:2024/05/06

出版日期:2026/04/28

Optical transmittance， dielectric properties and impedance spectroscopy of （1-x）（K_0.5Na_0.5）NbO₃-xSr_0.7La_0.2ZrO₃ ceramics

Hu Baofu, Wei Houren, Yang Zaiwen, Liu Bingguo, Xu Jian, Wang Jian, Du Baoli

School of Physics & Electronic Information Engineering， Henan Polytechnic University， Jiaozuo 454003， Henan， China

Abstract: Objectives To investigate the optical transmittance， conduction mechanism， and dielectric relaxation behavior of （K_0.5Na_0.5）NbO₃-xSr_0.7La_0.2ZrO₃ （KNN-SLZ） ceramics.  Methods Lead-free KNN-SLZ ceramics were prepared by a conventional solid-state method. The microstructure was tailored by introducing Sr_0.7La_0.2ZrO₃（SLZ）. The phase structure and morphology were characterized by X-ray diffraction （XRD） and scanning electron microscopy （SEM）. The optical transmittance and dielectric properties were measured using a UV-Vis-NIR spectrophotometer and an LCR meter， respectively. Temperature-dependent impedance and electric modulus spectra were analyzed using an impedance analyzer.  Results The KNN-SLZ ceramics exhibit a pseudocubic perovskite structure with grain sizes ranging from 0.1 to 0.5 μm， along with a small amount of pores. The submicron grain size contributes to enhanced optical transmittance. With increasing SLZ content， the transmittance gradually improves， reaching 45% at a wavelength of 2 000 nm in the infrared region. Within the frequency range of 10²~2×10⁶ Hz， the dielectric constant exceeds 2 050 and the dielectric loss remains below 0.1， indicating good frequency stability. Impedance spectroscopy reveals a non-Debye relaxation behavior. The relaxation process at high temperature is mainly attributed to the short-range hopping of ionized oxygen vacancies. In the medium- and high-frequency regions， the temperature dependence of conductivity weakens， and the conduction mechanism transitions from long-range charge migration at low frequency to short-range hopping between localized states at high frequency.  Conclusions The excellent optoelectronic properties indicate that KNN-SLZ ceramics have promising applications in transparent electronic devices.

Key words: （K_0.5Na_0.5）NbO₃;lead-free transparent ceramics;electrical property;impedance analysis;dielectric constant