Cation dependence of raman scattering in alkali borate glasses

摘要: Abstract A Raman scattering study of alkali borate glasses in the system xR 2 O · (1 − x ) B 3 for R = Li , Na K has been carried out to understand role mass cation determining B-O network glasses. results show that lighter cations favour a stronger which three-dimensional BO 4 groups are attached large ring while heavy not easily inserted interstices. The introduction favours formation non-bridging oxygens make comparatively weak and hence result decrease glass transition temperature ( T g ). short correlation range these different + also estimated its dependence on is discussed terms coordination change boron from three four. frequency temperature-reduced intensities have calculated glasses, it found spectra represent true vibrational density-of-states. This corresponds well theoretical obtained basis Martin-Brenig model. band around 770 cm −1 whose position varies with changes both composition ion explained by considering simple model based two weakly coupled harmonic oscillators.