The α, β Transformation of Quarts

Abstract

Sir C. V. Raman and T. M. K. Nedungadi have discussed in NATURE of January 27 a remarkable series of photographs showing the spectrum of monochromatic light scattered in a quartz crystal at various temperatures up to 530° C, not far from the transition point at 575° C. Their results are of special interest to me because they serve to confirm my opinion that, at any transition temperature (including the melting point), some kind of resonance occurs between two frequencies which characterize the two phases concerned. In other words, the transition takes place when there is close agreement between a frequency characteristic of the first phase and another frequency characteristic of the second phase. Since resonance may occur when this agreement is not quite exact, an explanation is possible of the fact that for many substances the setting point is not quite the same as the fusion point.