Controlling core-shell structures in (Na1/2Bi1/2)TiO3 based ceramics and investigating their impact on electrical properties

电陶瓷通常通过掺杂外来离子来优化，例如，电导率，磁性和铁电性。然而，在研究中，我们经常遇到这种策略的局限性。复合材料通常被证明是另一种创造具有新性能或改进性能的材料的方法。然而，这对于通常需要在高温下烧结的陶瓷来说是非常复杂的。有趣的是，基于（Na1/2Bi1/2）TiO3的材料仅通过常规的固态合成就可以形成核壳复合材料。复合材料的形成与铁电性质的剧烈变化有关。这种材料表现得更像反铁电体。这种陶瓷在用作电容器材料时具有巨大的优势，可以同时存储高功率密度的高电能。在使用电能方面，面临着满足关于有效传输能量的新要求的挑战。特别是来自可再生能源的能源可能会受到很大的波动，这使得很难提供所有可供使用的能源。高效、大功率、高能电容器是实现这一目标的重要组成部分。这就是为什么基于上述电陶瓷的电容器可能是一个解决方案。如何对材料进行改性以获得所需的性能仍然完全不清楚。虽然已知缺陷化学的变化会导致重大变化，但我们离控制其性质还很遥远。因此，研究缺陷的化学性质和电学行为的起源是非常重要的。我们想用现在的项目来解决这个问题。

Electroceramics are usually optimized by doping them with foreign ions to modify, for example, electrical conductivity, magnetic properties, and ferroelectric properties. In research, however, we often come up against the limits of this strategy. Composite materials often prove to be another way to create materials with new or improved properties. However, this is very complicated for ceramics, which usually have to be sintered at high temperatures. Interestingly, materials based on (Na1/2Bi1/2)TiO3 can form core-shell composites solely through regular solid-state synthesis. The formation of the composite correlates with a drastic change in the ferroelectric properties. The material behaves more like an anti-ferroelectric. Such a ceramic would have enormous advantages when used as a capacitor material for storing high electrical energy with high power density at the same time. In the area of the use of electrical energy, there is the challenge of meeting the new requirements with regard to efficient energy transmission. Energy from renewable sources, in particular, can be exposed to high fluctuations, and this makes it difficult to provide all of the energy for use. Efficient, high-power, high-energy capacitors are an important component in achieving the goal. This is why capacitors based on the aforementioned electroceramics could be a solution here. How the material has to be modified in order to obtain the desired properties is still completely unclear. Although it is known that variations in the defect chemistry lead to major changes, we are still far away from the control of the properties. Therefore, an investigation of the defect chemistry and the origin of the electrical behavior is of great importance. We want to address that with the present project.