(Ba<sub>0.55</sub>Sr<sub>0.45</sub>)<sub>1−x</sub>La<sub>x</sub>Ti<sub>1.01</sub>O<sub>3</sub>-Bi<sub>0.5</sub>Na<sub>0.5</sub>TiO<sub>3</sub> Positive Temperature Coefficient Resistivity Ceramics with Low Curie Temperature (~−15 °C)

oleh: Wanlu Xu, Wenwu Wang, Xiaoshan Zhang, Ping Yu

Format: Article
Diterbitkan: MDPI AG 2024-04-01

Deskripsi

Positive temperature coefficient of electrical resistivity (PTCR) materials with low Curie temperature have been paid increasing attention lately. In this study, PTCR materials with a Curie temperature of approximately −15 °C were investigated by La<sup>3+</sup> doping Ba<sub>0.55</sub>Sr<sub>0.45</sub>TiO<sub>3</sub> ceramics. It could be expected to meet the requirements of thermal management systems for low-temperature control. In addition, a trace amount of Bi<sub>0.5</sub>Na<sub>0.5</sub>TiO<sub>3</sub> (BNT) was employed to improve the resistivity and the PTCR performance. A significant PTCR effect was achieved with a high resistivity jump of nearly four orders of magnitude, a high temperature coefficient of ~28.76%/°C, and a narrow transition temperature span of 22 °C in the (Ba<sub>0.55</sub>Sr<sub>0.45</sub>)<sub>0.99875</sub>La<sub>0.00125</sub>Ti<sub>1.01</sub>O<sub>3</sub>-0.0025Bi<sub>0.5</sub>Na<sub>0.5</sub>TiO<sub>3</sub> ceramics. The PTCR enhancement mechanism of BNT is discussed.