The Study on Thermal Transformations of Muscovite by Weissenberg Camera with High Temperature Apparatus

Abstract

A high temperature apparatus for Weissenberg camera employing equi-inclination diffraction geometry was designed and constructed. The apparatus was successfully operated at temperatures up to 1, 350°C for a long run, but at temperatures up to about 1, 400°C for a short run. And, it is possible to control the atmosphere of the furnace. The inclination angle of this apparatus was designed to be 45° with equi-inclination diffraction geometry.
The study on the thermal transformation of muscovite was made by using Weissenberg camera with a high temperature apparatus described here. The thermal transformation process is characterized by a structural continuity reflected by the topotactic transformation throughout the entire transformation process. The topotactic relations among muscovite, muscovite anhydride, spinel type phase, and corundum were as follows:
aM//aM.an.//[112] Sp.//[2110] Co.
bM//abM.an.//[110] Sp.//[0110] Co.
c*M//c*M.an.//[111] Sp.//[0001] Co.
where the suffixes M., M. an., Sp. and Co. signify muscovite, muscovite anhydride, spinel type phase, and corundum respectively.