CC BY 3.0 DEKritz, AntjeMüller, Matthias2024-01-082024-01-081994https://oa.tib.eu/renate/handle/123456789/14405https://doi.org/10.34657/13435Glasses containing microcrystals of CuBr or CuCl show two characteristic absorption peaks caused by excitonic transitions. If temperature is increased the peaks become wider and flatter, whereas the complete disappearance o f the excitonic peaks takes place in a narrow temperature range of 30 to 50 K. Absorption intensity in the UV region (at about 30 000 cm⁻¹) increases simultaneously. The reason for these reversible changes is the melting of the microcrystals about 200 K below the melting point of the corresponding bulk crystals. The melting point depends on size and composition of the microcrystals.enghttps://creativecommons.org/licenses/by/3.0/de/660Article