ESR Studies of Cupric Ion in Various Oxide Glasses

ESR spectra of cupric ions in borate, silicate, and phosphate glasses were analyzed by the LCAO MO method of Maki and McGarvey. The covalency of the B 2g π‐orbital was found to change with the bond strength of the network‐former. Particularly it reflected clearly the weakening of BO bonds in alkali borate glasses with increasing alkali content or with increasing ratio of BO 4 tetrahedra to BO 3 triangles. Microscopic fluctuations in glass were found essential to explain the line shape of the hyperfine structure. Two different states of cupric ions were observed in some quenched glasses.