XCV.—The polysulphides of barium and calcium

Thermodynamic evaluation and optimization of the (Ca+C+O+S) system

“…However, they were not able to perform additional detailed analyses of crystalline products in order to ascertain other properties, such as crystallographic data and melting or decomposition temperatures of the products. Robinson and Scott [36] also attempted to synthesise calcium polysulphides thermally by reacting metallic calcium with liquid sulphur close to the boiling temperature of sulphur, but CaS was the only observed solid product.…”

“…The products were synthesised in anhydrous alcohol or ammonia solutions at low temperatures. Only Robinson and Scott [36] reported crystalline polysulphides. However, they were not able to perform additional detailed analyses of crystalline products in order to ascertain other properties, such as crystallographic data and melting or decomposition temperatures of the products.…”

“…Metals with a large ionic radius, such as the alkali metals and barium, have been shown to form a liquid phase at compositions more sulphur-rich than their corresponding sulphides [4,36] with the liquid phase stable down to considerably lower temperatures than the melting temperature of the solid sulphide. The liquid phase consists of a mixture of chain-like polysulphide ions, S 2À n .…”

“…The melting temperature of CaS is 2798 K [23]. Several solid, amorphous calcium polysulphides have been synthesised [34][35][36][37]. The reported stoichiometries of the amorphous calcium polysulphides are CaS 2 , CaS 3 , CaS 4 , and CaS 5 .…”

Validity of using methanol for studying the microstructure of cement paste

“…Calcium methoxide (Ca(OCH3),): surface area of 60 x lo3 m2 kg-'. This material, for which the XRD and IR spectra matched published spectra [7], was prepared according to procedures described by Robinson and Scott [8].…”