Comment on Misconceived ASTM Definition of 'Glass' by A. C. Wright

摘要

In a recent Letter to the Editor of this journal, Wright(1) suggests that the 1945 definition of "glass" by ASTM is misconceived. His primary contention is that the word "fusion" would apply only to a few single component oxides such as SiO_2. Most glasses of commercial interest are however multicomponent which do more than "fuse". They do not melt individually to produce a mixture of liquids; rather, they react chemically to produce a molten, homogeneous liquid, generally of nonstoichiometric composition. Wright argues to include metallic glasses which have been formed through chemical bonding; however, he excludes amorphous solids which have been formed by vapour-deposition techniques. Amorphous solids do not display a glass transition on heating and may not be characterized by a fictive temperature at which the structure of glass after a few atomic vibrations would be identical to that of the supercooled liquid at the same temperature.