Chemical vapor depositing of metal fluorides

High Purity BeF2 and BeF2–AlF3 glasses have been deposited by the chemical vapor deposition technique using beryllium and aluminum 1,1,1,5,5,5 hexafluoroacetylacetonate, M(hfa)x, as source compounds. Be(hfa)2 and Al(hfa)3 provided the source for both metal and fluorine. Thermal decomposition of M(hfa)x forms two exclusive products, MFx and a volatile organic byproduct, 2,2‐difluoro‐2,3‐dihydro‐5‐trifluoromethylfuran‐3‐one. This unique intramolecular fluorine transfer from the ligand to the metal provides a method for depositing various high purity metal fluorides. Optically clear BeF2 and BeF2–AlF3 glass samples have been made with the correct stoichiometry and a very low level of impurities.