Line width measurements of Cr 3+ in a zinc borate glass

Abstract

The temperature dependence of the homogeneous line width ( Γ h) of the R-line of Cr 3+ in 4ZnO·3B 2O 3 glass in the region between 15 K and room temperature has been measured. We found that Γ h has a T 2 dependence down to approximately 30 K. Below 30 K the data do not follow the power law, T 2. The results are compared with those of Cr 3+ in mullite and ED2 silicate glasses where the crossover was observed at about 80 K and with the data for Eu 3+ in zinc borate and other glasses. The comparison indicates that the local environment affects Γ h. In fact, the Cr 3+ ions appear to form more defined complexes with the oxygen ligands than do the Eu 3+ ions, which have a larger distribution of sites in the glass.