Refractive indexes of ionic melts

Refractive Index of Molten LaCl3-KCl, LaCl3-NaCl, and LaCl3-CaCl2 Mixtures

“…In the low temperature range (<400°C), our data are in good agreement with theirs as shown before [7], However, we estimated that the accuracy of wave-front shearing interfer ometry at higher temperatures [14] (> 800°C) is nearly equal to that of goniometry. It should also be mentioned that very precise refractive indexes have little effect on the estimation of the molar refractivity and the electronic polarizability since the molar volume has been measured up to only four sig nificant figures.…”

“…The refractive index n; of the mixtures decreased linearly with increasing temperature in the same manner as described previously [12]. As pointed out by Gustafsson et al [3,13,17], at low temperatures the refractive indexes could be better fitted by qua dratic functions of temperature.…”

“…Other expressions have been proposed as dispersion formulas, but we have ascertained experimentally that (2) is best applicable to ionic melts [7,12]. As before [7], we have used the empirical equation n (/, t) = (P + Q/)} + R//.4) + (7\ + QJ/.2 + R Ja a) t, (3) where the constants P to R{ have been determined by the method of least squares.…”

“…As before [7], we have used the empirical equation n (/, t) = (P + Q/)} + R//.4) + (7\ + QJ/.2 + R Ja a) t, (3) where the constants P to R{ have been determined by the method of least squares. The results for molten LaCl3-KCl, LaCl3-NaCl, and LaCl3-CaCl2 mixtures are given in Table 1, where e is the stan dard error on fitting.…”

“…Also, the molar refractivity of molten salt has been reported to increase slightly with rising of tempera ture [1 -7], The electronic polarizability of an ion or a molecule has so far been evaluated from the re fractive index of alkali halide crystal [8], liquid crystal [9], aqueous electrolyte solution [10], and organic liquid [11]. The values for pure melts have been summarized in a previous paper [12].…”