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

A bstract 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% of 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 phosphorus‐oxygen 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.