Composition dependence of the optical absorption spectra of cupric ion in sodium borosilicate glass melts

Optical absorption spectra of Cu2+ d–d transition peak in sodium borosilicate glasses and their melts were measured from room temperature to 1100 K. In the case of borate glass free from silicon, increase of the temperature above Tg shifts the peak position to the low energy side and decreases the peak height. Peak width is gradually increased with the increase in temperature. On the other hand, in the case of silicate glass free from boron, peak width is decreased with the increase in temperature from room temperature to liquidus temperature. In addition, peak height is slightly decreased with the temperature increase in this temperature range. Further increase of the temperature makes the peak width large. In borosilicate glasses, temperature dependence of the optical absorption spectra is different both from borate and from silicate, and the temperature dependences of the peak position and of the peak height are very small. Temperature dependence of the peak width depends on the boron/silicon ratio.