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

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.