Stoichiometry vibrational modes and structure of molten Nb_2O_3-K_2S_2O_7 mixtures. A raman spectroscopy study

摘要

The dissolution reaction of Nb_2O_5 in pure molten K_2S_2O_7 has been studied and high temeprature Raman spectroscopy has been used for determining the vibrational and structural properties of the Nb(V) complex(es) formed according to the reaction Nb_2O_5+nS_2o_7~(2-) -C~(2n-).By means of a recently derived simple formalism for correlating relative Raman band intensities with the stoichiometric coefficient, n, it was found that n=3. The most characteristic bands of the NbO(SO_4)_3~(3-) complex unit formed occur at 1185, 1046, 937, 690, 664, 411 and 265 cm~(-1). The results are discussed in terms of a possible structural model.