Glass ceramics are in every day's use - scratch-resistant as hot plate, heatproof and transparent as oven doors and cooking dishes. Huge and powerful telescope mirrors used to explore our space are made of glass ceramics. And even the replacement of human bone is today made of glass ceramics.
All of this is possible because scientists and technicians were able to find ways to selectively influence the crystal growth in glass melts. In this way, glass gains totally new properties.
Within the project INTERCONY further steps will be taken towards a material transforming long-wave light into light of short waves. This means one could turn Infrared light into Ultraviolet light (so called up-conversion effect). For this reason, the INTERCONY team is looking for new nano-scaled glass ceramics (i.e. nano-crystals embedded in a glass) to be used in photonics - a branch where light is applied as medium to transport information and energy ia applied as a tool.
First a glass is prepared by mixing the compounds and heating up the powder up to temperatures of ~ 1500°C. Then the glass melt is casted into a mould and "cooled" down to room temperature very slowly resulting in a stressfree glass. The conversion active crystals are formed afterwards during a temperature treatment where the number and the size of nano-crystals are controlled by the temperature and the time of the process. The glass ceramic then is ready to be investigated and tested by different methods (e.g. electron microscopy, fluorescence spectroscopy, X-ray diffraction) to check the intensity of the up-conversion effect.
Figure Insight into the transparent glass ceramic (figure above) making the nano-crystals visible by electron microscopy
Based on fundamental investigations concerning the formation of interfaces during nucleation and crystal growth the INTERCONY team wants to develop new method for the production of nano-structured glass ceramics. In this glasses a huge amount of very small crystals are found. Important is that these crystals must not scatter the light. To target the crystallisation the scientists combine theoretical and experimental investigations with computerised simulations.
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