Study on the Properties and Conduction Mechanism of Strontium-Lead Titanate Based Composite Thermistor Materials

摘要

The properties and conduction mechanism of Yttrium-doped (Sr_(0.45)Pb_(0.55))TiO_3 ceramics thermistor materials were investigated. The materials prepared by the wet chemical method exhibited the significant NTC characteristics below T_c besides the ordinary PTC properties above T_c. The negative temperature coefficient of resistivity is better than -3%/°C and the minimum resistivity is at the magnitude of 100 Ω·cm. The conduction mechanism was studied by the complex impedance analysis and microstructure analysis. The results showed that NTC behavior in the materials was originated from the grain boundary and closely related to the composition and microstructure of the grain boundary phase.