Y_(2)O_(3)掺杂及烧结温度对SrTiO_(3)基陶瓷电学性能的影响

Effects of Y_(2)O_(3)Doping and Sintering Temperature on the Electrical Properties of SrTiO_(3)Based Ceramics

【目的】获得综合电学性能良好的SrTiO_(3)基电子功能陶瓷。【方法】选取稀土氧化物Y_(2)O_(3)作掺杂剂,用典型电子陶瓷工艺制样,利用压敏电阻参数仪和数字电桥测试并结合扫描电镜(SEM)观察,探讨了Y_(2)O_(3)的掺杂量及烧结温度对SrTiO_(3)基陶瓷电学性能和微观结构的影响规律。【结果】随着Y_(2)O_(3)掺杂量从0.3 mol.%渐增至1.8 mol.%,陶瓷的压敏电压V_(1mA)先减后增,非线性系数α逐渐减小,而相对介电常数ε_(r)和介电损耗tanδ均总体上呈升高趋势。掺0.9 mol.%Y_(2)O_(3)时,陶瓷综合电学性能较好。提高烧结温度可获得更理想的微观结构并进一步提升电学性能,经1425℃、3 h保温烧成、掺0.9 mol.%Y_(2)O_(3)的SrTiO_(3)基陶瓷的综合电学性能最优:V_(1mA)=7.2 V、α=10.8、ε_(r)=3.8×10^(4)、tanδ=2.1×10^(-2)。【结论】适量掺杂Y_(2)O_(3)并合理控制烧结温度,可使SrTiO_(3)基陶瓷具有理想的微观结构,从而表现出优良的电学性能。

[Purposes]This paper aims to obtain SrTiO_(3)based electronic functional ceramics with good comprehensive electrical properties.[Methods]The samples were prepared by typical electronic ceramic processes with selected rare earth oxide Y_(2)O_(3)dopant,the effects of Y_(2)O_(3)doping amount and sintering temperature on the electrical properties and microstructures of SrTiO_(3)based ceramics were investigated using varistor parameter instrument and digital bridge testing and scanning electron microscopy(SEM)observations.[Findings]With the doping amount of Y_(2)O_(3)gradually increases from 0.3 mol.%to 1.8 mol.%,the breakdown voltage V_(1mA)of the ceramics increases firstly and then decreases,and the nonlin⁃ear coefficientαgradually decreases,while the relative dielectric constantε_(r)and dielectric loss tanδgenerally show an upward trend.The ceramics with 0.9 mol.%Y_(2)O_(3)doping possess better comprehensive electrical properties.Increasing the sintering temperature can obtain a more ideal microstructure and fur⁃ther improve the electrical properties.SrTiO_(3)based ceramics doped with 0.9 mol.%Y_(2)O_(3)and sintered at 1425℃for 3 hours have the best comprehensive electrical properties:V_(1mA)=7.2 V,α=10.8,ε_(r)=3.8×10^(4),tanδ=2.1×10^(-2)。[Conclusions]An appropriate amount of Y_(2)O_(3)doping and reasonable control of sintering temperature can enable SrTiO_(3)based ceramics to have an ideal microstructure,thereby exhibit⁃ing excellent electrical properties.