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boldmath Characterization of the BaBiO3-doped BaTiO3 positive temperature coefficient of a resistivity ceramic using impedance spectroscopy with Tc=155℃ 下载免费PDF全文
BaBiO3-doped BaTiO3 (BB-BT) ceramic, as a candidate for lead-free positive temperature coefficient of resistivity (PTCR) materials with a higher Curie temperature, has been synthesized in air by a conventional sintering technique. The temperature dependence of resistivity shows that the phase transition of the PTC thermistor ceramic occurs at the Curie temperature, Tc=155 ℃, which is higher than that of BaTiO3 ( ≤ 130 ℃). Analysis of ac impedance data using complex impedance spectroscopy gives the alternate current (AC) resistance of the PTCR ceramic. By additional use of the complex electric modulus formalism to analyse the same data, the inhomogeneous nature of the ceramic may be unveiled. The impedance spectra reveal that the grain resistance of the BB-BT sample is slightly influenced by the increase of temperature, indicating that the increase in overall resistivity is entirely due to a grain-boundary effect. Based on the dependence of the extent to which the peaks of the imaginary part of electric modulus and impedance are matched on frequency, the conduction mechanism is also discussed for a BB-BT ceramic system. 相似文献
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以自制MgxZn1-xO∶Al陶瓷为靶材,采用磁控溅射工艺在石英玻璃衬底上制备了MgxZn1-xO∶Al紫外透明导电薄膜,研究了Mg掺杂量和退火温度对MgxZn1-xO∶Al薄膜结构和光电性能的影响。X射线衍射表明,在x≤0.4的范围内,MgxZn1-xO∶Al薄膜为六角纤锌矿结构,当x≥0.6时,MgxZn1-xO∶Al薄膜为立方结构。当x≤0.4时,随着x值的增加,薄膜的电阻率有所增加,但其光学吸收边产生明显的蓝移,禁带宽度显著增大,透射光谱扩展到紫外区域。退火对薄膜电阻率影响显著,随着退火温度的增加,样品的电阻率先大幅度降低,后有略微的回升,600℃时电阻率最低,且吸收边较未退火时有一定的蓝移。 相似文献
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采用传统的固相法制备了(1-x)(K0.5Na0.5NbO3-LiSbO3-BiFeO3)-xCuFe2O4 (x=0.1, 0.2, 0.3, 0.4) 磁电复合陶瓷, 并借助X射线衍射仪、扫描电镜和磁电耦合系数测试仪等对复合陶瓷的微结构和性能进行了分析. 结果表明, 复合陶瓷的K0.5Na0.5NbO3-LiSbO3-BiFeO3和CuFe2O4物相之间发生了一定的离子相互扩散作用, 且两相的颗粒大小匹配性较好. 随着CuFe2O4含量增加, 复合陶瓷的压电系数从130 pC/N减小到30 pC/N, 饱和磁致伸缩系数从4.5×10-6增加到12.4×10-6左右, 磁电耦合系数表现出先增加后减小, 在x=0.3时获得最大的磁电耦合系数9.4 mV·cm-1·Oe-1.
关键词:
0.5Na0.5NbO3-LiSbO3-BiFeO3')" href="#">K0.5Na0.5NbO3-LiSbO3-BiFeO3
2O4')" href="#">CuFe2O4
磁电耦合 相似文献
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采用传统固相合成法和制备工艺,在1040℃制备了{0.996 [0.95( Na0.5 K0.5)NbO3-0.05LiSbO3 ]-0.004FeBiO3}+x mol; CuO(KNN-LS-BF+x mol; CuO)无铅压电陶瓷,研究了CuO掺杂量对陶瓷结构和性能的影响.结果表明,CuO的低温促烧作用明显,微量CuO的掺入并没有改变陶瓷体系的相结构,但对陶瓷的压电和介电性能有明显影响.随CuO掺杂量的增加,陶瓷的d33、kp、εr均是先升高后降低,并在x=0.15时,d33、kp、εr分别达到最大值222 pC/N、0.36、1223.14;Qm也是先升高后降低,不过是在x=0.3时达到了最大值66.02.而tanδ则是先降低,在x=0.45达到最小值2.5;后又开始回升.在x=0.15时,所制备压电陶瓷有最好的综合性能:d33=222pC/N,kp=0.36,εr=1223.14,tanδ=3.3;,Qm =52.27. 相似文献
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采用超声喷雾热解法,在玻璃基底上一步合成了In2S3薄膜.研究了衬底温度对In2S3薄膜的结构、表面形貌、电学和光学性能影响.结果表明:所制备的In2S3薄膜均具有沿(220)面择优取向生长特性且无其他杂相,衬底温度对薄膜的均匀性、致密度、结晶程度均有明显影响,并因此影响薄膜的光电性能.薄膜的导电件随着衬底温度的升高迅速增强,但足在衬底温度为350℃时有所降低.衬底温度为300℃所制备的薄膜在可见光区透光率最高达到90;以上,禁带宽度达到2.43 eV. 相似文献