Holmium(III) fluoride

Holmium(III) fluoride is an inorganic compound with a chemical formula of HoF3.

Preparation
Holmium(III) fluoride can be produced by reacting holmium oxide and ammonium fluoride, then crystallising it from the ammonium salt formed in solution:


 * Ho2O3 + 6NH4F ⟶ 2HoF3 + 6NH3 + 2H2O

It can also be prepared by directly reacting holmium with fluorine:


 * 2Ho + 3F2 -> 2HoF3

Properties
Holmium(III) fluoride is a yellowish powder that is insoluble in water. It has an orthorhombic crystal system (corresponding to β-YF3 ) with the space group Pnma (space group no. 62). However, there is also a trigonal low-temperature form of the lanthanum(III) fluoride type.