X‐ray Study of Lime‐phosphate and Lime‐borate Glass*

Abstract

X-ray diffraction patterns have been made of two lime-phosphate glasses with compositions of 23% and 28% of CaO by weight, and of one lime-borate glass with 25% o f CaO. Fourier analyses of these patterns were carried out, and the radial distribution curves were plotted. In the lime-phosphate glasses, each phosphorus is tetrahedrally bonded to 4 oxygens at a distance of 1.57 A, and each oxygen is bonded to either 1 or 2 phosphorus atoms. The calcium ions, Ca++, are situated in the holes in the phosphorusoxygen network and have about 7 oxygen neighbors. In the lime-borate glass, some of the borons are triangularly bonded to 3 oxygens, and the others are tetrahedrally bonded to 4 oxygens.

Role of vitrons in alkali silicate binary glasses

“…This method has been applied to several soda-silicate glasses [4], to potash silicate glasses [5], and to some soda silicate glasses containing lime [6]. Such work has been done, also, on some simple borate glasses [7], and phosphate glasses [8].…”

“…Compu ted possi bilities X·ray e ,·id ence R em" rk s and estima tes of E s tim ated shielding (8) pea ks lJartJief '1'ilton [5] (W arren)…”

Local structure around phosphorus and silicon in the CaO–SiO2–PO2.5 system

“…In all spectra, the peak with the chemical shifts of around 3 ppm was confirmed and the shapes of the spectra at a constant CaO/SiO 2 ratio were in accordance with each other within the limits of experimental error. According to Grussaute et al [13], this chemical shift of 3 ppm is that of the monophosphate complex ion PO 4 3− in the CaO-SiO 2 -PO 2.5 system.…”

“…They confirmed that the distribution ratio was constant up to 2 mass% of phosphorus in the slag and that it increased linearly beyond 2 mass%. To explain this phosphate-concentration dependence of the distribution ratio, they presumed that Reaction (1) took place and that the predominant species of phosphorus in the slag was the monophosphate complex ion PO 4 3− , up to 2 mass% of the phosphorus in the slag. At higher phosphorus concentrations, Reaction (2) occurred and the diphosphate complex ion P 2 O 7 4− was the dominant species in the slag phase.…”

“…As a result, chemical and physical properties such as basicity, viscosity, and electrical conductance are influenced by structural changes [1]. To elucidate the structural dependencies of these properties, the compositional dependence of the structures of slag/glass such as silicate, borate, and phosphate has been widely studied [2][3][4].…”