Articles you may be interested inComposition dependence of the viscosity and other physical properties in the arsenic selenide glass systemThe configurational entropy theory of glass formation is used to derive the composition dependence of the glass transition temperature (Tg) and of supercooled liquid transport properties for binary mixtures which obey the laws of regular solutions. The relations between expressions derived subject to specified approximations and known empirical equations are shown, and the parameters of the latter are thereby identified with defined measurable quantities. The predicted composition dependence of Tg is compared with experimental data from binary mixtures with satisfactory agreement.

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BIO. B11. and 0 17 NMR were used to study B 2 0 3 glass. BID NMR was employed to determine the most probable values and the Gaussian widths (0') of the distributions of the quadrupole coupling constant (Q,J and the asymmetry parameter (1). The resulting values are Q~, = 5.51 MHz. O'Qcc = 0.21 MHz. 1)0 = 0.12. and 0' ~ = 0.043. These values are consistent with results using B11 NMR. The 0 17 NMR spectra are obtained and analyzed using two sites: site 1 is characterized by Q~, = 4.69 MHz. 0' Qc, = 0.10 MHz. 1)0 = 0.58; site 2 is characterized by Q~, = 5.75 MHz. 1)0 = 0.4. and 0' ~ = 0.2. Only small distributions are present for site 1 and for Q" of site 2. A Townes-Daily calculation was employed. using the boroxol ring model of B 2 0 3 glass. to determine the charge distributions and the B-O-B angle outside the boroxol rings. The results are consistent with a structure composed of randomly oriented boroxol rings.(2)where y is the gyromagnetic ratio, H o is the applied magnetic field assumed to lie in the z direction, and I. is the component of the nuclear spin operator I in the direction of the applied magnetic field. H Q can be written asH 802