Spinodal decomposing glass ceramic with tailored porous, thermal and dielectric properties

在该项目中，将开发一种新型微晶玻璃材料，在湿法化学浸出过程中提供纳米级的孔隙率。材料组合物的组成将使得在温度处理时发生调幅分解，并产生额外的可浸出相。这种材料将通过特定的流延工艺来制造。为此，原始材料成分被调整为浆料，并浇注到定义的板材厚度。分解相的形状和大小主要取决于退火步骤。通过这种方法，可以实现发生相的均匀分布。在Erlangen有一些合适的玻璃用于正在研究的这一过程。烧结后，对分解相进行湿法化学刻蚀，孔隙度可调。根据孔隙率和孔的大小，将研究合适的薄膜金属化，覆盖孔并适合用作加热器元件。为此，将对薄膜的电学性能和长期稳定性进行研究。作为演示，将制造皮拉尼压力传感器，展示这些材料的低导热系数和适用于传感器的适用性。此外，材料的介电常数将作为多孔介质材料的进一步有趣的性质而被研究。

Within the project a novel glass-ceramic material will be developed providing a nanoscale porosity after a wet chemical leaching process. The material composition will be composed so that while a temperature treatment a spinodal decomposition occurs and an additional leachable phase originates. This material will be manufactured by a specific tape casting process. For that, the original material composition is conditioned as slurry and cast to a defined sheet thickness. The shape and size of the decomposed phases depends mainly on the annealing steps. By this procedure a homogeneous distribution of the occurring phase can be achieved. There are some suitable glasses for this process being investigated in Erlangen. After sintering the decomposed phase will be wet chemically etched and the degree of porosity can be adjusted. Depending on the porosity and the pore size a suitable thin film metallization will be investigated covering the pores and being suitable e.g. as heater element. For that, the film will be investigated with respect to its electrical performance and long term stability. As demonstrator, a Pirani pressure sensor will be manufactured, showing the low thermal conductivity and suitability of these materials for the applicability within sensors. Additionally, the permittivity of the material will be investigated as further interesting property of porous dielectric materials.