Effect of SiO2 sintering additive on the positive temperature coefficient of resistivity (PTCR) behavior of (Bi1/2Na1/2)0.10Ba0.90TiO3 + CaO ceramics
Effect of SiO2 sintering additive on the positive temperature coefficient of resistivity (PTCR) behavior of (Bi1/2Na1/2)0.10Ba0.90TiO3 + CaO ceramics
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DOI：
10.1016/j.materresbull.2017.02.005
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发表时间：
2017-05
影响因子：
5.4
通讯作者：
Daniel Mächler;J. Töpfer
中科院分区：
文献类型：
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作者：
Daniel Mächler;J. Töpfer
采用混合氧化物法制备了无铅（Bi 1/2Na 1/2）0.10Ba 0.90TiO 3陶瓷，其中CaO的添加量为3.5mol %，陶瓷具有正温度系数电阻率（PTCR）特性。需要纳米晶TiO 2粉末作为原料，以允许在800 °C煅烧期间完全形成相。样品在空气中于T < 1250 °C烧结，得到室温电阻较低的热敏电阻陶瓷，在Tc= 155 °C时电阻率显著上升。微结构的形成和电性能对二氧化硅的添加敏感。在空气中加入0.05wt%SiO2烧结助剂烧结后，获得了室温电阻率ρRT= 80 Ωcm，居里温度下电阻率变化ρmax/ρ min超过两个数量级的致密PTCR热敏陶瓷。
Lead-free (Bi1/2Na1/2)0.10Ba0.90TiO3ceramics with 3.5 mol% CaO addition and positive temperature coefficient of resistivity (PTCR) behavior were prepared by the mixed-oxide route. Nanocrystalline TiO2powder is required as raw material to allow complete phase formation during calcination at 800 °C. Samples were sintered at T < 1250 °C in air to give thermistor ceramics with low room-temperature resistance and significant rise of resistivity at Tc= 155 °C. The microstructure formation and electrical properties are sensitive to silica addition. Dense PTCR thermistor ceramics with low room-temperature resistivity ρRT= 80 Ωcm and resistivity change ρmax/ρminover two orders of magnitude at the Curie temperature were obtained after sintering in air with 0.05 wt% SiO2sintering additive.