Electronic Spectra and Structure of Molten Mixtures xNa2O–Re2O3–(100–x)B2O3 (Re = Pr, Nd)

Abstract

The results of the spectral studies of molten mixtures xNa₂O–Re₂O₃–(100–x)B₂O₃ (Re = Pr, Nd; x = 0–50) at 1273 K are reported. In both the mixtures, the cyclical changes in the coordination numbers of boron atoms, for which the limits of the concentration variation of fourfold coordinated boron groups are specified, are observed with an increase in the concentration of Na₂O. It is shown that the coordination numbers of the Pr(III) and Nd(III) ions increase from 6 to 8 in the range from 0 to 10 mol % of Na₂O.