摘要
以碳酸钡、碳酸锶、二氧化锡和二氧化钛等为原料,La2O3为掺杂剂,在不同温度下烧结,制得了Ba0.92Sr0.08Ti0.9Sn0.1O3(BSTS)系介质瓷。XRD结果表明,所有的BSTS试样都形成了单一的钙钛矿结构晶相,通过SEM分析了La2O3对试样的微观形貌的影响,发现La2O3的加入可有效地抑制晶粒的尺寸。测试了在1 kHz频率条件下试样的电容量C、介质损耗因数D和-25^+95℃试样的C和D,得到了试样的居里温度TC及相对介电常数εr随温度的变化曲线。结果表明,在室温下,试样的εr随着La2O3加入量的增加,呈一直减小的趋势,介电损耗tanδ随着La2O3加入量的增加,则呈先减小后增加的趋势,TC随着La2O3加入量的增加逐渐向低温区移动,介电常数变化率Δε/ε则随着La2O3加入量的增加而逐渐下降。最终得到烧结温度为1 340℃,x(La2O3)=0.6%的Ba0.92Sr0.08Ti0.9Sn0.1O3介质瓷的εr最大值为3 825,tanδ最小值为20×10-4,Δε/ε为25.9%(25~85℃)。
Ba0.92Sr0.08Ti0.9Sn0.1O3 ceramics were prepared using BaCO3, SrCO3, SnO2 and TiO2 etc. as raw materials, La2O3 as dopant. The X-ray diffraction patterns indicated that all the BSTS specimens possessed the perovskite polycrystalline structure. SEM was also employed to observe the surface morphologies, the result revealed that the introduction of La2O3 into BSTS can control the grain growth. The capacitance C and dielectric loss factor D of the samples were measured at 1 kHz. Some properties of the samples, such as the Curie temperature and the variation rate of Er with different temperature were acquired. The results showed that εrOf the samples decreases, tan δ first decreases then increases with increasing amount of doped La2O3, the Curie temperature Tc shifts to lower temperature and the variation rate of relative dielectric constant △Aε/ε decreases with the introduction of La2O3. εr ,tanδ and △Aε/ε showed the optimum values of 3 825,20× 10^- 4 and 25.9%（ 25 ℃ to 85 ℃） at 0.6%0 La2O3-doped under 1 340℃ sintering temperature respectively.
出处
《压电与声光》
CSCD
北大核心
2009年第4期556-558,561,共4页
Piezoelectrics & Acoustooptics
基金
教育部博士点基金资助项目(20040056055)
