Yttrium phosphate, YPO4, is the phosphate salt of yttrium. It occurs in nature as minerals xenotime[1] and weinschenkite.[2]
Yttrium phosphate can be obtained by reacting yttrium chloride and sodium phosphate, or by reacting yttrium nitrate and diammonium hydrogen phosphate in solution:
Yttrium phosphate can also be prepared by the reaction of yttrium(III) oxide and diammonium hydrogen phosphate:[3]
Yttrium chloride and phosphoric acid are mixed at 35~40°C, and then ammonia solution is added dropwise to react:[4]
Yttrium phosphate belongs to the tetragonal crystal system, and the unit cell parameters are a=0.68832 nm, c=0.60208 nm. It can exist as a monohydrate, dihydrate or the anhydrous form. The dihydrate belongs to the monoclinic crystal system, the space group is B 2/b, and the unit cell parameters are a=0.648 nm, b=1.512 nm, c=0.628 nm, β=129.4°, Z=4.[5]
Yttrium phosphate reacts with concentrated alkali to form yttrium hydroxide.[6]
Yttrium phosphate is used as a catalyst and is a potential containment material for nuclear waste. Ce3+-doped yttrium phosphate shows luminescence in the UV range and can be used for tanning lamps.[7] [8] Double-doped materials such as Ce3+-Tb3+ have also been reported.