Effect of Ba0.5Bi0.5Fe0.9Sn0.1O3 addition on electrical properties of thick-filmthermistors
(1. School of Materials Science and Engineering, Guilin University of Electronic Technology, Guilin 541004, China;
2. School of Information and Communication, Guilin University of Electronic Technology, Guilin 541004, China)
2. School of Information and Communication, Guilin University of Electronic Technology, Guilin 541004, China)
Abstract: Thick-film thermistor with negative temperature coefficient (NTC), low room-temperature resistivity and modest thermistor constant was screen-printed on the alumina substrate by the combination of with Ba0.5Bi0.5Fe0.9Sn0.1O3. The electrical properties of the thick films were characterized by a digital multimeter, a Keithley 2400 and an impedance analyzer. The results show that with the Ba0.5Bi0.5Fe0.9Sn0.1O3 content increasing from 0.05 to 0.25, the values of room-temperature resistivity, thermistor constant and peak voltage of the thick films increases and are in the ranges of 1.47-26.5 Ω·cm, 678-1345 K and18.9-47.0 V, respectively. The corresponding currentat the peak voltage of the thick films decreases and is in the range of 40-240 mA. The impedance spectroscopy measurement demonstrates that the as-prepared thick films show the abnormal electrical heterogeneous microstructure, consisting of high-resistive grains and less resistive grain boundary regions. It can be concluded that the addition of Ba0.5Bi0.5Fe0.9Sn0.1O3 into improves the thermistor behavior and but also deteriorates the current characteristics.
Key words: NTC thick films; ; Ba0.5Bi0.5Fe0.9Sn0.1O3; electrical property