The Variable Thermal Sensitivity of Strontium-Lead Titanate Semiconducting Ceramics

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• 作者：Jingchang Zhao ; Longtu Li ; Jianquan Qi and Zhilun Gui
• 关键词：(Sr ; Pb)TiO3 materials ; PTCR effect ; NTCR effect
• 刊名：Journal of Electroceramics
• 出版年：2002
• 出版时间：2002
• 年：2002
• 卷：9
• 期：3
• 页码：173-177
• 全文大小：71 KB

文摘

Strontium-lead titanate semiconducting ceramics with low room temperature resistivity (_RT) and variable NTCR-PTCR composite effects were fabricated at different sintering conditions. Both _RT and the NTCR effect decreased at the higher heating rate or doping excess of PbO. After the heat-treatment at 950°C, the transformations from PTCR to NTCR-PTCR characteristics were observed in excess PbO-doped samples. According to the results, it is assumed that the lead vacancies (V_Pb) in the grain boundary layers degenerate the conductivity of strontium-lead titanate semiconducting ceramics and the NTCR behaviors below the Curie temperature are ascribed to the electron detrapping of acceptor defects with increasing temperature.