Ammonium Fluoride is an inorganic compound with formula NH4F. It crystallizes as small colorless prisms, have a sharp saline taste, and is exceedingly soluble in water. To produce ammonium fluoride ammonia gas is passed into ice-cooled 40% hydrofluoric acid or by heating 1 part ammonium chloride with 2.25 parts sodium fluoride and separating the ammonium fluoride by sublimation. It can be used as intermediates, plating agents and surface treating agents, process regulators, processing aids specific to petroleum production, solvents for cleaning or degreasing, electrical, and electronic parts. It is also employed in a new hydrothermal synthesis of of complex fluorides NaHoF4 and NaEuF4, these compounds have the fluorite structure and are important for solid-state lasers as well as for photoluminescence and magnetic characteristics.