Yttrium(III) phosphate

Yttrium phosphate, YPO₄, is the phosphate salt of yttrium.^[1] It occurs in nature as minerals xenotime^[2] and weinschenkite.^[3]

Yttrium(III) phosphate

Names
IUPAC name Yttrium phosphate
Identifiers
CAS Number	13990-54-0
3D model (JSmol)	Interactive image
ChemSpider	8488871
ECHA InfoCard	100.034.341
EC Number	237-790-3
PubChem CID	10313406
CompTox Dashboard (EPA)	DTXSID80884522
InChI InChI=1S/H3O4P.Y/c1-5(2,3)4;/h(H3,1,2,3,4);/q;+3/p-3 Key: UXBZSSBXGPYSIL-UHFFFAOYSA-K InChI=1/H3O4P.Y/c1-5(2,3)4;/h(H3,1,2,3,4);/q;+3/p-3 Key: UXBZSSBXGPYSIL-DFZHHIFOAS
SMILES [O-]P(=O)([O-])[O-].[Y+3]
Properties
Chemical formula	YPO4
Molar mass	183.877
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

A sample of the mineral xenotime (YPO₄)

Preparation

Yttrium phosphate can be obtained by reacting yttrium chloride and sodium phosphate, or by reacting yttrium nitrate and diammonium hydrogen phosphate in solution:^[2]

YCl₃ + (NH₄)₃PO₄ → YPO₄ ↓ + 3 NH₄Cl

Y(NO₃)₃ + (NH₄)₂HPO₄ → YPO₄ ↓ + 2 NH₄NO₃ + HNO₃

Yttrium phosphate can also be prepared by the reaction of yttrium(III) oxide and diammonium hydrogen phosphate:^[4]

Y₂O₃ + 2 (NH₄)₂HPO₄ → YPO₄ + 2 NH₃ + 3 H₂O

Yttrium chloride and phosphoric acid are mixed at 35~40°C, and then ammonia solution is added dropwise to react:^[5]

YCl₃ + H₃PO₄ + 3NH₃•H₂O ^35-40°C
_→ YPO₄ + 3NH₄Cl + 3H₂O

Properties

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.^[6]

Yttrium phosphate reacts with concentrated alkali to form yttrium hydroxide.^[7]

Uses

Yttrium phosphate is used as a catalyst and is a potential containment material for nuclear waste.^[2] Ce³⁺-doped yttrium phosphate shows luminescence in the UV range and can be used for tanning lamps.^[8][9] Double-doped materials such as Ce³⁺-Tb³⁺ have also been reported.