The best known crystal is the ice crystal. No two crystals are 100% alike.

A synthetically produced crystal like sapphire is used for example as a substrate for today usual GaN-LEDs. Due to the boom in the LED-technology the demand for high quality sapphire crystals increased significantly. Currently the technology allows the growth of crystals with a weight per piece up to 300 kg.

To manufacture sapphire crystals, alumina is molten at temperatures up to 2300 °C in a high vacuum furnace and a seed crystal focuses the solidifying monocrystal. This results in optically very pure microstructures. Optically very accurate crystals have to be grown in order to achieve a high yield in this long and energy consuming process.
 

For the insulation of these furnaces our heat-shields out of zirconia bricks and granular materials are used.

Our products are suitable for Czochralski method.