Ternary Chlorides and Bromides of the Rare-Earth Elements

TERNARY CHLORIDES AND BROMIDES OF THE RARE-EARTH ELEMENTS 

Compound formation in the alkali-metal halide/rare-earth metal trihalide systems seems to be limited to the four following formula types  

The synthetic route deseribed here, starting with aqueous solutions of the appropriate amounts of alkali-metal halides and rare-earth metal halides. 

A RE 2 X7 cesium PRASEODYMIUM CHLORIDE (CsPr CI,) AND POTASSIUM DYSPROSIUM CHLORIDE (KDyjCI,) 

The clear solutions in 1 or 2 are slowly evaporated to dryness by using a heating plate or an infrared lamp. The residue is then transferred to a corundum crucible (size 10 x 60 mm), and this is inserted into a fused-quartz tube in the center of a tubular furnace. (To prepare larger quantities, e.g.. 

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Ternary Chlorides and Bromides of the Rare Earth Elements 3... 

An alternative is the reaction of the respective sesquioxides with (NH4)Hp2, in analogy to the ammonium chloride (bromide) route. In principle, this is a two-step procedure with the formation of a ternary fluoride first and, secondly, its thermal decomposition (see below). When elemental fluorine is available, the direct fluorination of the rare earths or any of their salts is also a possibility. Ternary fluorides are obtained by a solid state reaction of the respective binary components in sealed gold or platinum tubes. 

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