Composition and Temperature Dependence of Structural Changes in Borosilicate Glasses by Spectrometer

Abstract

We investigated the particularity of temperature and composition changes in <TEX>$xNa_2O{\cdot}(52.5-x)B_2O_3{\cdot}47.5SiO_2$</TEX> glasses by use of FT-IR, <TEX>$^{11}B$</TEX> NMR, Raman spectrometer. From FT-IR and <TEX>$^{11}B$</TEX> NMR spectrometer, we thought that tetrahedral boron, <TEX>$BO_4$</TEX> units are created <TEX>$N_4$</TEX> increasing tendency generated near <TEX>$600^{\circ}C$</TEX>. It's expected that composition ana heat treatment directly contributed to structural changes, this changes are following to <TEX>$Na_2O$</TEX> increasing or decreasing. caused by <TEX>$N_4\;and\;BO_4$</TEX> units are caused by relatively increasing or decreasing in the glasses' structure. Particularly, <TEX>$BO_4$</TEX> units are converted to <TEX>$BO_3$</TEX> units after <TEX>$600^{\circ}C$</TEX> heat treatment for 50h in the composition of <TEX>$x<18(R<0.5,\;R=Na_2O/B_2O_3\;mol\%)$</TEX>. On the order hand, <TEX>$BO_3$</TEX> units are converted to, <TEX>$BO_4$</TEX> units after <TEX>$600^{\circ}C$</TEX> heat treatment for 50h in the composition of <TEX>$x{\geq}18\;(R>0.5)$</TEX>. This particularity of composition and temperature dependence of structural changes are similarly represented by Raman analysis results.