HIGH-TEMPERATURE PSHB MATERIALS - MOLECULAR DOPED XEROGELS AND THE PROBLEM OF SPECTRAL DIFFUSION

Organic-inorganic hybrid solids have been prepared using sol-gel proce ss. The sol-gel technique offers a room temperature attractive approac h for introducing molecules into amorphous inorganic materials. Molecu lar doped inorganic or hybrid (organic-inorganic) xerogels are reveale d to be suitable for high temperature PSHB. With molecules covalently grafted or chemically bonded to the inorganic network, a maximum tempe rature of 120 K has been achieved. Temperature cycling experiments rev eals the importance of spectral diffusion in these systems. Spectral d iffusion appears to be the most important difficulty to overcome.