Strontium Fluoride, SrF₂

Strontium Fluoride, SrF₂, is obtained in regular octahedral crystals by fusion of strontium chloride with potassium hydrogen fluoride or with sodium fluoride, or of strontium iodide with manganese fluoride. It may also be prepared by the precipitation of strontium chloride solution with potassium fluoride, neutralisation of strontium oxide or carbonate by hydrofluoric acid, or by the action of gaseous hydrofluoric acid on strontium chloride at red heat. The heat of formation of strontium fluoride from its elements is 237.02 Cal.

The density is 4.20 – 4.24, and the melting-point 1400° C. On heating in air at 1000° C. a certain amount of strontium oxide is formed. Hydrochloric acid passed over it at red heat easily decomposes it into strontium chloride and hydrofluoric acid.

The solubility of strontium fluoride in water is only slight, being 117.1 mgm. per litre at 18° C., as determined by conductivity methods. The heat of solution is -2.1 Cal.