White monoclinic crystals; refractive index 1.56; density 7.1 g/cm3; sublimes at 970°C.
용도
Hafnium(IV) fluoride is used as Vacuum deposition.
생산 방법
Hafnium tetrafluoride is prepared by careful thermal
decomposition of ammonium fluorohafniate in an oxygen-
free atmosphere or by passing anhydrous hydrogen
fluoride over hafnium tetrachloride at 300℃. Direct synthesis
from the elements is incomplete because the product
merely forms a film on the metal. Ammonium fluorohafniate
can be prepared by crystallization from an aqueous
hydrofluoric acid solution by adding ammonium
fluoride.
