This project is funded by the program “NanoMatFutur” from the German federal ministry of education and research for the built up of a junior research group. It deals with new capacitor material for electronics with high temperature and power requirements.

These requirements results from higher demand of energy from renewable energy sources, demand of more efficient energy storage and conversion and increasing electrification of parts in automotive and aviation applications.

Heavy hydraulic systems should be replaced by light and more economically efficient electronic systems. Hence, actuator and sensor electronics are installed in regions, in which they are exposed to extreme temperatures (-50 to 300°C and above) and temperature variations. Furthermore, energy generation from renewable sources is usually not achieved continuously. Therefore, the components are exposed to power fluctuation with occasionally high power peaks further leading to intensive temperature increase. In the field of electro-mobility, energy recuperation combines high temperature and high power requirements as well. Regarding capacitors, however, there is now appropriate material available so far which can withstand industrial requirements. Hence, capacitors can be seen as a key components for the realization of high temperature electronics.

Promising materials are sodium bismuth titanate based ceramics. However, these are new and very complex systems. Their physical properties can usually not be rationalized based on experience with other ceramics. This is especially problematic with regard to reliability and degradation of the system. The aim of this project is the provision of a sodium bismuth titanate (NBT) based capacitor material which fulfills very high temperature and power requirements. Additionally, the influence factors changing material properties during synthesis shall be investigated so that the ceramic is optimized according to industrial requirements and demands. In depth investigations of physical properties aids defining the application range, durability and reliability of the ceramic compounds. This is especially necessary because the capacitors are interesting for applications with very high reliability requirements (e.g. aviation, automotive applications). Usually, only materials are used in this case, which have proven themselves in applications with less reliability demands. As this is not valid for the new material it is important to gain in depth information on defect chemistry to be able to derive reliability parameters.