Inversion of quartz solid solutions at cryogenic temperatures
Quartz solid solution crystals of six different compositions were obtained from crystallization of glass powders belonging to the Li2O–Al2O3‐SiO2 (LAS) system. They were analyzed in situ by laboratory‐based X‐ray diffraction down to cryogenic temperatures (−190°C). Temperature‐resolved analysis of their lattice parameters allowed determination of the critical inversion temperature Tc in these materials, marking the displacive phase transition from a high‐quartz‐ to a low‐quartz‐like lattice. Integrating available data from other literature sources, an updated phase diagram for the occurrence of high and low quartz solid solution phases is provided for the LAS system; these data are expected to support future development of functional materials relying on these crystalline phases.