Raman studies of lithium borophosphate glasses

Abstract

In the past few years, studies of the changes in Raman spectra and ionic conductivity in some glasses in silicate, borate and phosphate systems showed that the ionic conductivity of the glass was mainly dependent on the total number of active ions Li + or Na +, but there was also an effect of the glass structure on conductivity. When Al 3+ and/or B 3+ ions were present in the glass in the form of AlO 4 and BO 4 and the excess negative charge on them was compensated by the active cation ion, the glass would have higher ionic conductivity. A detailed investigation of the Raman spectra of Li 2OB 2O 3P 2O 5 glasses has shown that besides phosphate groups, such as metaphosphate (PO 3) n n− , tetraphosphate (P 4O 13) 6−, triphosphate (P 3O 10) 5− and pyrophosphate (P 2O 7) 4−,a nd borate groups, such as diborate (B 4O 7) 2− and chain-type metaborate (BO 2) −, there may also be different of kinds of phosphate groups containing BO 4 units, (BOP) 0 and (BOP) −, groups present in this glass system. The active ability of Li + ions present in (B 4O 7) 2–, phosphate groups with BO 4 units and BO 4 units and (BOP) − groups is higher than those present in various phosphate groups with non-bridging oxygen(s).