Effect of planetary ball milling and elutriation processes on the α-β phase transition of quartz

Abstract

SEM observation, dynamic light scattering measurement, powder X-ray diffraction measurement, and differential thermal analysis were carried out on quartz powder ground by a planetary ball mill and on fine-grained quartz that was further separated by elutriation. The results of this study showed that the crystallite size of α-quartz decreased with increasing milling time, but there was a trend of increasing the aggregate size. The amorphous phase was evaluated from the XRD baseline intensity at around 2θ=11°. The amount of amorphous phase generated by the ball milling increased in α-quartz with milling time. As a result, the areas of both endothermic and exothermic peaks corresponding to the α-β and β-α phase transitions decreased and finally disappeared completely. Even by decreasing the areas of endothermic and exothermic peaks, no obvious changes were observed in the α-β and β-α phase transition temperatures. The results of this study suggest that differential thermal analysis can be used as a useful tool to evaluate the initial process of amorphization in α-quartz.