Use of BaO-aided structural change of BaO-ZnO-TeO_2 glass to enhance the optical properties of its doped activators by optimizing their surrounding ionic field

摘要

Spectroscopic studies of BaO effect on the Yb~(3+)-doped BaO-ZnO-TeO_2 glasses of varied BaO content reveal that the integrated emission of constant amount of Yb~(3+) in these glasses increases with the increase in BaO. Excitation spectra exhibit a phonon progression of～150 cm~(-1), while FTIR spectra of the glasses show a phonon at～700 cm~(-1); intensity of both increases with increase in BaO. The phonons are identified, respectively, as the rotational and stretching vibrations of loosely bound tellurite (TeO_3~-/(Te_2O_5)~(2-)) units of the host's structure, concentration of which increases with the increase in BaO. Specific volume data, XRD, HRTEM investigations suggest that large Ba~(2+) ions in these glasses attract the tellurite units toward its vicinity inducing a compaction. Ba~(2+) -substituted Yb~(3+) ions in the glass because of higher charge density attract the tellurite units even closer and experience greater ionic field exhibiting efficient luminescence. Glass is potential host for designing new generation efficient optical materials.