Review of the Relation of Density and Refractive Index to the Composition of Glass: Ii *

Abstract

IndexIn many series of glasses, refractive index does not vary linearly with composition, and the relationship that does result depends on the type of glass and the composition range studied.Zs~himrner,~T using data after Abbe and Schott, plotted refractive indices against (a) equivalent weights of LizO, ZnO, BaO, and PbO per 100 parts of B203; (b) equivalent weights of Na20, ZnO, BaO, and PbO per 100 parts of alkali-silicate glass; and (c) percentage of B203 in alkali-silicate glass. In no case was a straight line produced, and there was a curve-maximum in (c), The following qualitative conclusions were drawn : (i) The mean refractive indices of Bz03, fused silica, and alkali-silicate glass are raised by the solution of metallic oxides in increments not proportional to the molecular weight of the dissolved oxide; (ii) that variation with concentration is not direct is evident because the optical constants decreased for LizO (in B203), Na20 (in SOz), and ZnO (in B2O3 and alkali-silicate glass) and increased for PbO and BaO; (iii) Bz03 up to 15% in potassium-silicate glass increases refractive index, and further additions reverse the effect.Peddle58 plotted refractive index against moles of a variable constituent. For the soda-lime-silica glasses studied, he was able to calculate that composition necessary to produce a definite value of refractive and dispersion i n d e~.~g His graphs did not indicate a straight-line relation between refractive index and composition.

Thermal and some physical properties of glasses in the La2O3−CaO−B2O3 ternary system

“…Therefore, glasses with increased La 2 O 3 content are expected to have higher mean polarizability values which are reflected in the n D values, as given in Table 3. This is also in agreement with the empirical correlations of q and n D in glasses [28,29].…”

The Gladstone–Dale relation: Applications in oxide glasses

“…Conversely, Sun and coworkers had the opinion that the Gladstone-Dale relation was not very accurate for computing properties other than volume and refractivities. [22][23][24] However, like many others, they recognized the usefulness in being able to easily compute values for density or index of refraction with known information.…”

“…During the same time that Young and Finn were doing their research, others were also commenting on how the Gladstone-Dale relation could be used for glasses. [21][22][23][24] For instance, Huggins noted that for boron-containing glasses, there should be different specific refractive values for tetrahedrally and trigonally coordinated structures. 21 He was one of the first to state that compared to other formula that correlates index of refraction to density, the Gladstone-Dale relation is the most simplistic to use, an opinion that most researchers who work with the formula agree to.…”

“…During the same time that Young and Finn were doing their research, others were also commenting on how the Gladstone–Dale relation could be used for glasses 21–24 . For instance, Huggins noted that for boron‐containing glasses, there should be different specific refractive values for tetrahedrally and trigonally coordinated structures 21 .…”

Espectroscopia linear e não linear em vidros aluminosilicato de cálcio dopados com Térbio

“…Deste modo, apesar da boa convergência da Eq. (2.4), para determinar a polarizabilidade de compostos de ), existem muitos casos de divergências na "aditividade da refração de Lorentz-Lorenz", ou seja, a expansão ou contração nas nuvens eletrônicas dos íons, influencia nos resultados da polarizabilidade[52,53].Dikshit e Kumar [54] compararam dados da polarizabilidades de íons em um grande número de cristais haletos e calcogenetos obtidos por diferentes modelos para o cálculo da polarização em cristais. Desta análise confirmaram que a soma das polarizabilidades eletrônicas de um cátion e do ânion no estado livre são, em geral, maiores que a soma correspondente no estado cristalino, isto é: + + − > + + − , em que + e − são representam a polarizabilidade do cátion e do ânion no estado livre + e − são as polarizabilidades correspondentes no cristal.…”