Tilquin, JY.
Duveiller, P
Glibert, Jacques
[UCL]
Claes, Paul
[UCL]
The redox ratio, R = C-Cr(VI)/C-Cr(III), in a glass-forming liquid with composition Na2O . 1.2SiO(2) . 1.2B(2)O(3) to which was added Na2CrO4 . 4H(2)O was directly determined at 1000 degrees C under various oxygen partial pressures using voltammetric techniques and high temperature spectrophotometry. The linearity of the log(R) vs log(P-O2) function was confirmed. The absorption spectra of the chromium species were recorded in the quenched glass at normal temperature and in the liquid at 1000 degrees C. The affects of temperature on the charge transfer bonds of Cr(VI) and on the d-d bands of Cr(III) are discussed. Whereas, the d-d bands related to Cr(III) in an octahedral coordination undergo a broadening and a large displacement towards the LR while increasing temperature, no variation of the charge transfer band of Cr(VI) is observed. (C) 1998 Elsevier Science B.V.
Bibliographic reference |
Tilquin, JY. ; Duveiller, P ; Glibert, Jacques ; Claes, Paul. Comparison between high temperature UV-visible spectroscopy and electrochemistry for the in situ study of redox equilibria in glass-forming melts. In: Journal of Non-Crystalline Solids, Vol. 224, no. 3, p. 216-224 (1998) |
Permanent URL |
http://hdl.handle.net/2078.1/45337 |