Yttrium(III) fluoride is an inorganic chemical compound with the chemical formula YF<sub>3</sub>. It is not known naturally in "pure" form. The fluoride minerals containing essential yttrium include tveitite-(Y) (Y,Na)<sub>6</sub>Ca<sub>6</sub>Ca<sub>6</sub>F<sub>42</sub> and gagarinite-(Y) NaCaY(F,Cl)<sub>6</sub>. Sometimes mineral fluorite contains admixtures of yttrium.
YF<sub>3</sub> can be produced by reacting fluorine with yttria or yttrium hydroxide with hydrofluoric acid.
Yttrium(III) fluoride has a refractive index of 1.51 at 500 nm and is transparent in the range from 193 nm to 14,000 nm (i.e. from the UV to IR range).
Pure yttrium can be obtained from yttrium(III) fluoride by reduction with calcium.
Yttrium(III) fluoride crystallizes in the orthorhombic crystal system, with space group Pnma (space group no. 62), with the lattice parameters a = 6.3537 ÃÂ , b = 6.8545 ÃÂ , c = 4.3953 ÃÂ . Yttrium is nine times coordinated by fluorine atoms.
It occurs as the mineral waimirite-(Y).
Yttrium(III) fluoride can be used for the production of metallic yttrium, thin films, glasses and ceramics.
Conditions/substances to avoid are: acids, active metals and moisture.