X-Ray Diffraction and the Structure of Glasses

JSGT 1922 V06 T068-T101

Earlier results on the diffraction of X-rays by glasses have been extended to include vitreous cadmium pyrophosphate, selenium, lithium metaborate, antimony and bismuth sesquioxides, lead metasilicate and a number of the more common glasses in everyday use. Figures are given for the band spacings of all glasses so far examined. In agreement with the previous work it is concluded that the diffraction bands can, in general, be explained on the basis of the idea of minute crystals or groups of atoms regularly arranged over very small volumes. The reasons for the formation of glasses are discussed in the light of the new experimental work. It is suggested that the probability of the formation of a glass is high for those substances, the normal crystalline forms of which are such that the forces binding the atoms together are either strongly directional or localised in character. The possibilities of understanding the patterns of the more complex commercial glasses are discussed. It is thought that the regular groups of atoms may not be so definite in composition or size as in the case of the simpler glasses. Finally the connection between this work and the more general problem of the melting of solid bodies is brought out and suggestions are made.

J. T. Randall & H. P. Rooksby