R. Pascova et C. Russel, THERMODYNAMICS AND DIFFUSION OF IRON IN HOMOGENEOUS AND PHASE-SEPARATED SODIUM BOROSILICATE MELTS, Journal of non-crystalline solids, 208(3), 1996, pp. 237-246
Voltammetric measurements were carried out at temperatures in the rang
e of 600 to 1200 degrees C in both homogeneous and phase separated gla
ss melts of different compositions in the Na2O-B2O3-SiO2 system doped
with 0.5 mol% Fe2O3. At high temperatures, the current-potential curve
s were fairly similar to those recorded, e.g., in soda-lime-silica gla
sses. At temperatures below the immiscibility temperature T-C, peak sp
litting in the curves occurs, the two different states can be attribut
ed to iron in the silica-rich and in the berate-rich phase. Peak split
ting, however, also occurs up to temperatures about 250 degrees C high
er than T-C. This behaviour is interpreted by a layer adjacent to the
electrode formed by a boron-rich phase.