Notiz: Sulphate Rotator Phases in Polarised Light

Abstract

Li 2 S0 4 has a well defined high-conducting fee phase in the temperature range 577-860 °C, and LiNaS0 4 a bcc phase in the range of 518-614 °C. Both salts were studied in polarised light during sequences going from melt, through the cubic phase into the "room temperature" phase, and back to the cubic phase. The two cubic sulphate phases are compared with organic plastic rotator phases, especially regarding the formation of vapour snakes.