Ricerche sui vetri del sistema NaO-BO
U.r. and Raman spectra of glasses of composition (x = 2, 3, 4, 5, 6 e 9) are reported. By comparison with known crystalline structure of borate and polyborate u.r. spectra, it is possible to reveal a gradual boron transformation from trigonal to tetrahedral coordination, when the NaO percentage in glass composition rises. The Raman spectra too support this behaviour, moreover we may characterize the presence of BO(O) rings in the glass structure by a typical band near 800 cm. Heating the materials...