基于Y3+/Zr4+单掺杂及共掺杂CaCu3Ti4O12的高温热敏传感器研究

Perovskite-like CaCu3Ti4O12 has become a new research frontier in the microelectronic device field because of its high permittivity and good temperature stability. In particular, the variable valence cations and oxygen vacancy of the CaCu3Ti4O12 provide an essential condition for the research on its thermistor properties..This proposal intends to design and synthesize new high-temperature thermistor sensors by Y3+/Zr4+ single-doped and co-doped perovskite-like CaCu3Ti4O12, focuses on their relationship between composition, microstructure and high-temperature thermistor property. To obtain the single perovskite-like high-temperature thermistor sensors through investigating the effects of the ion doping on the phase structure of thermistor sensors. To reveal the high-temperature thermistor mechanism through investigating the effects of the ion doping on microstructure and high-temperature electrical properties of thermistor sensors. To reveal the defect interaction mechanism of high-low temperature through analyzing the temperature dependence of carrier concentration and mobility, and probing into the effects of the defect (metal vacancy, oxygen vacancy) interaction on the high-low temperature conductivity of thermistor sensors. To probe into the mechanism of high-temperature stability of thermistor sensors through comparing microstructure and electrical properties of before and after high-temperature aging under different aging atmosphere (air, vacuum)..The achievements of this project will have great significance in the research thermistor properties of perovskite-like CaCu3Ti4O12 and the design and synthesis of new high-temperature thermistor sensors.

类钙钛矿CaCu3Ti4O12由于其高的介电常数和好的温度稳定性已成为微电子器件领域新的研究热点。其中，CaCu3Ti4O12中的变价阳离子及氧空位为其具有热敏特性提供了必要条件。.本项目拟以Y3+/Zr4+单掺杂及共掺杂类钙钛矿CaCu3Ti4O12来设计合成新型高温热敏传感器，研究其组成、微观结构与高温热敏性能的关系。通过研究离子掺杂对其相结构的影响规律，获得单一类钙钛矿型高温热敏传感器；通过研究离子掺杂对其微观结构及电性能的影响规律，揭示其高温热敏机理；通过分析热敏传感器载流子浓度、迁移率随温度的变化关系，探讨缺陷（金属空位、氧空位）相互作用对其高低温导电性能的影响规律，揭示其高低温缺陷作用机制；比较研究其在不同气氛（空气、真空）中高温老化前后的微观结构及电性能，揭示其高温稳定性机理。.项目研究成果对研究类钙钛矿CaCu3Ti4O12热敏性能及设计合成新型高温热敏传感器具有重要意义。

在航空航天及汽车工业，陶瓷基高温热敏电阻器被认为是替代铂电阻和热电偶的潜在高温温度传感器，已成为热敏传感器领域重要的发展方向。本项目通过Y3+、Zr4+等单掺杂、共掺杂及高电导相复合制备了系列CaCu3Ti4O12、ACu3Ti4O12(A=Sr, La2/3, Ca, Y2/3)基高温热敏陶瓷材料及器件，重点研究了离子掺杂量、复合度、制备工艺对器件结构与高温电性能的影响规律，揭示了离子掺杂改性的物理机制及高温导电机理，阐明了高温稳定性机制。此外，拓展研究了同属Ca基复氧化物的CaCeNbMO8（M=W或Mo）型高温热敏陶瓷材料结构及高温电性能。取得的重要结果主要有：.1. 通过Y3+、Zr4+、La3+、Fe3+等离子单掺杂可有效调节CaCu3Ti4O12热敏传感器电性能，电导主要通过电子在Cu+与Cu2+及Ti3+与Ti4+间传输形成。掺杂态CaCu3Ti4O12热敏传感器电性能表现出低B高阻特性、有望满足25~900℃宽温区高温应用；Fe3+掺杂实现了CaCu3Ti4O12热敏器件在300℃以上阻温关系的线性化。.2. 通过Y3+/Zr4+共掺杂CaCu3Ti4O12可在保持热敏特性基础上提高材料的致密度和均匀性，进而实现电输运性能与高温稳定性的协同调控；通过LaMnO3复合CaCu3Ti4O12一方面降低了B值、拓宽了应用温度范围，另一方面使电阻漂移率从23%下降到4%以下，显著提升了高温稳定性。.3. 比较研究了氧化物固相法和Pechini法制备的ACu3Ti4O12基热敏陶瓷材料及器件结构与电性能。Pechini法有效降低了陶瓷的烧结温度、克服了化学计量比偏差和阳离子空位扩散，从而减少了连续高温环境中的金属离子偏析，使其对氧气具有独特的不敏感性，进而提高了老化稳定性。.4. 揭示了CaCeNbMO8基高温热敏陶瓷高低温电导机制，探讨了类质同晶转变、稀土离子诱导偏振降阻效应及其伴生的变温电子补偿机制，为高温热敏陶瓷材料结构从类钙钛矿向新型白钨矿的研究与探索提供了理论基础。.项目研究成果在Applied Physics Letters、Journal of the American Ceramic Society等期刊发表SCI论文15篇；授权国家发明专利2项、申报国家发明专利2项，对于新型白钨矿高温热敏陶瓷材料及器件的研究具有重要的理论参考价值。