| 题名 | 线性热敏复合陶瓷材料BaSn0.96Sb0.04O3-CoFe0.5Co1.5O4的制备及性能研究 |
| 作者 | 常善南 |
| 学位类别 | 硕士 |
| 答辩日期 | 2016-05-27 |
| 授予单位 | 中国科学院大学 |
| 授予地点 | 北京 |
| 导师 | 张惠敏 |
| 关键词 | 线性复合热敏材料 微观结构 电性能 R-T 特性 热稳定性 |
| 学位专业 | 材料物理与化学 |
| 中文摘要 | 负温度系数(Negative Temperature Coefficient)热敏电阻是一类随温度升高电阻率显著降低的热敏元件，通常阻温关系呈指数型变化，在实际使用中，通常与其它元件进行补偿使其线性化，使某一温度范围内的阻-温特性呈线性，用这种方法获得的线性温区相当窄，会使热敏电阻的可靠性大大降低。 线性NTC因其阻-温特性呈线性变化，温度系数小，精度高并能够简化电路，使用起来方便可行等优点而广泛应用，具体表现为在控温时，无需调整比例；用于温度补偿时，可以满足大范围补偿的要求；用于测温时，测量结果不需要查表和绘制曲线。 为了解决在实际应用中非线性NTC所带来的问题，本文采用氧化物固相法，将BaSn0.96Sb0.04O3 与CoFe0.5Co1.5O4 复合制备(BaSn0.96Sb0.04O3)1-x-(CoFe0.5Co1.5O4)x (0.1≤x≤0.9)和(BaSn0.76Bi0.2Sb0.04O3)1-x-(CoFe0.5Co1.5O4)x (0.1≤x≤0.9) 热敏陶瓷材料体系。利用X射线衍射分析(XRD)、热重-差热分析(TG-DSC)、扫描电子显微镜(SEM)、阻-温特性以及老化性能等测试手段，对制备的热敏电阻材料粉体和陶瓷样品进行了分析和表征，主要研究内容与得到的结论如下： （1）采用固相法制备BaSn0.96Sb0.04O3、CoFe0.5Co1.5O4氧化物粉体材料，通过TG/DSC分析确定了BaSn0.96Sb0.04O3粉体材料的最佳煅烧温度；进而制备(BaSn0.96Sb0.04O3)1-x-(CoFe0.5Co1.5O4)x (0.1≤x≤0.9)系列线性NTC热敏复合材料，1200℃烧结后陶瓷的XRD分析结果表明：当x=0时，陶瓷体为单一的立方钙钛矿结构，随着复合度x的增加，样品由立方钙钛矿相转变为尖晶石相。电学特性结果表明，电阻率随着CoFe0.5Co1.5O4含量的增大而增大，室温电阻率、B25/50、活化能及线性灵敏度的变化范围为1.61×105Ω·cm-1.06×106Ω·cm、389.19K-568.39K、0.034eV-0.049eV、254Ω/℃-2386Ω/℃。在0~200℃呈现良好的线性，线性误差变化范围为1.88%~16.47%。结果表明，(BaSn0.96Sb0.04O3)0.5(CoFe0.5Co1.5O4)0.5复合材料ρ25为3.1×105Ω·cm，线性误差达到1.88%，温度系数为-4.56×10-3/℃，其线性灵敏度为512 Ω/℃，其线性误差最小，线性灵敏度较高，可作为一种适用于宽温区测量的线性复合热敏电阻材料。 （2）(BaSn0.96Sb0.04O3)1-x-(CoFe0.5Co1.5O4)x (0.1≤x≤0.9)系列复合陶瓷在125℃老化500h后，其电阻漂移率在1.6%-8.1%范围内。其中(BaSn0.96Sb0.04O3)0.5(CoFe0.5Co1.5O4)0.5材料体系电阻漂移率为3.4%。(BaSn0.96Sb0.04O3)0.1(CoFe0.5Co1.5O4)0.9表现出较高的热稳定性，电阻漂移率仅为1.6%。 （3）采用固相法制备了BaSn1-yBiySb0.04O3 (0.1≤y≤0.5)系列热敏材料，电学特性测试表明，随着Bi含量的增加，BaSn1-yBiySb0.04O3 (0.1≤y≤0.5)陶瓷的电阻率先减小后增大。其ρ25、B25/50及活化能的变化范围为207.41Ω·cm-1495.89Ω·cm、1901.47K-7411.23K、0.164eV-0.638eV。在0~100℃温度范围内，线性误差变化范围为6.12%~23.79%。结果表明，BaSn0.76Bi0.2Sb0.04O3材料体系适用于线性热敏材料，其线性误差为6.12%，ρ25为331.99Ω·cm，温度系数为-2.62×10-2/℃，其线性灵敏度为196 Ω/℃，线性误差较小，线性灵敏度较高。 （4）通过将(BaSn0.76Bi0.2Sb0.04O3)1-x-(CoFe0.5Co1.5O4)x (0.1≤x≤0.9)进行复合，Bi的掺入对复合陶瓷体微观结构及电学性能影响较大，在1200℃烧结温度下，室温电阻率随CoFe0.5Co1.5O4含量的增大而增大，电阻率、材料常数B25/50及活化能的变化范围为2697.46Ω·cm-9.65×106Ω·cm、674.95K-4227.35K、0.058eV-0.364eV。复合之后在x=0.1，0.3，0.7，0.9时材料体系线性误差较小，分别为8.65%，5.17%，4.71%，4.84%。结果表明，(BaSn0.76Bi0.2Sb0.04O3)0.3(CoFe0.5Co1.5O4)0.7材料体系适用于线性热敏材料，在0~110℃温度范围内，线性误差为4.71%，其线性灵敏度为3480Ω/℃，其线性误差较小，线性灵敏度高。通过Bi元素的掺入，有效提高了其复合后材料的线性灵敏度。 |
| 英文摘要 | It is well known that the electrical resistivity of most NTC thermistors is exponential function with regard to temperature, which brings much inconvenience to practical application. Since NTC thermistors are nonlinear elements, it must be linearized. Currently, the linear thermistor ceramics show the electrical properties and their application are commonly limited to narrow temperature range. The circuit compensation method is widely used in practice, that is to cascade or parallel the NTC resistor with a normal resistor so that a linear R-T relationship is made possibly under a certain temperature range. In this case, it requires a complex linear system comprised of multiple thermistors to extend the linear temperature range. However, the linear temperature range achieved through this method is rather limited and too complicated for practice.When served for temperature control, scaling adjustment is oftentimes necessary due to the deviation of sensitivity at different control points, when used for temperature compensation, compensations on a wider range are hard to be satisfied because of the characteristic difference between compensation element and thermistor, when dealing with temperature measurement, the uneven meter scale means that extra work on referring to tables and curves shall always apply. Therefore, those disadvantages of most NTC thermistors listed above would be settled by developing a new thermistor material which R-T character presents linear has received more attention in recent years . In this article, the linear thermistor material would like to be developed with a wide operating temperature range. The composite ceramic systems (BaSn0.96Sb0.04O3)1-x-(CoFe0.5Co1.5O4)x (0.1≤x≤0.9), (BaSn0.76Bi0.2Sb0.04O3)1-x-(CoFe0.5Co1.5O4)x (0.1≤x≤0.9) consist of spinel-structured CoFe0.5Co1.5O4 and perovskite-structured BaSn0.96Sb0.04O3 were prepared by classical solid state reaction. The calcined temperature of powder, ceramics phase structure, microstructure, R-T property and stability were characterized by TG/DSC, XRD, SEM, EDS, electrical measurement and aging test, respectively. The thesis can be summarized as follows: (1) BaSn0.96Sb0.04O3 and CoFe0.5Co1.5O4 powders have been prepared by convention solid-state reaction method. The calcined temperature of the BaSn0.96Sb0.04O3 powder materials are obtained by TG/DSC. At the same time, the X-ray diffraction analysis indicated that the composite ceramics consisted of two phases: a perovskite BaSn0.96Sb0.04O3 phase and a cubic spinel CoFe0.5Co1.5O4 phase. The composite ceramics were more dense and lower porosity with increasing the CoFe0.5Co1.5O4 content by SEM. The obtained ρ25 and B25/50 constants and activation energy of the composite ceramics were in the range of 1.61×105Ω·cm-1.06×106 Ω·cm、389.19K-568.39K、0.034eV-0.049eV, respectively. In particular, their relationship between R and T which differed from normal NTC displayed a good linear characteristic at 0-200℃. Its linear error is in the range of 1.88%~16.47%. The results also showed that the (BaSn0.96Sb0.04O3)0.5(CoFe0.5Co1.5O4)0.5 composite ceramic manifests a good linearity. Especially, the linear error is 1.88%. It could be used expediently in digital instrument and precision measurement. (2) The resistance drift rate of (BaSn0.96Sb0.04O3)1-x-(CoFe0.5Co1.5O4)x(0.1≤x≤0.9) series composite ceramics, aging at 125 ℃ after 500 h were from 1.6% to 8.1%. When x=0.9, the ceramic shows higher thermal stability. (3) BaSn1-yBiySb0.04O3 (0.1≤y≤0.5) series ceramics have been prepared by the same method. Based on the material system of XRD, SEM, EDS, R-T characteristic test, the obtained ρ25 and B25/50 constants and activation energy of the composite ceramics were in the range of 207.41Ω·cm-1495.89Ω·cm, 1901.47K-7411.23K, 0.164eV-0.638eV. The results also showed that when y=0.2, the material system of the BaSn0.76Bi0.2Sb0.04O3 manifests a good linearity. Especially, the linear error is 6.12%. (4) (BaSn0.76Bi0.2Sb0.04O3)1-x-(CoFe0.5Co1.5O4)x (0.1≤x≤0.9) series ceramics have been prepared by the solid-state method. Based on the material system of XRD, SEM, EDS, R-T characteristic test, the obtained ρ25 and B25/50 constants and activation energy of the composite ceramics were in the range of 2697.46Ω·cm-9.65×106Ω·cm, 674.95K-4227.35K, 0.058eV-0.364eV. The results also showed that by adjusting Bi doping amount, complex degree and preparation condition, the NTC composite ceramics with high resistivity. As x=0.1, 0.3, 0.7, 0.9, the linear error of the composite ceramics are 8.65%, 5.17%, 4.71%, 4.84%, respectively. The results also showed that the (BaSn0.76Bi0.2Sb0.04O3)0.3(CoFe0.5Co1.5O4)0.7 composite ceramic manifests a good linearity.The Bi-doped ceramics has a higher linear sensitivity. |
| 内容类型 | 学位论文 |
| 源URL | [http://ir.xjipc.cas.cn/handle/365002/4586]  |
| 专题 | 新疆理化技术研究所_材料物理与化学研究室 |
| 作者单位 | 中国科学院新疆理化技术研究所 |
| 推荐引用方式 GB/T 7714 | 常善南. 线性热敏复合陶瓷材料BaSn0.96Sb0.04O3-CoFe0.5Co1.5O4的制备及性能研究[D]. 北京. 中国科学院大学. 2016. |
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