Europium(III) phosphate

Europium(III) phosphate is one of the phosphates of europium, with the chemical formula of EuPO₄. Other phosphates include europium(II) phosphate (Eu₃(PO₄)₂) and europium(II,III) phosphate (Eu₃Eu(PO₄)₃).^[7]

Europium(III) phosphate

Identifiers
CAS Number	13537-10-5 hydrate: 14913-20-3 15259-63-9 semihydrate dihydrate: 34377-51-0 trihydrate: 49836-68-2
3D model (JSmol)	Interactive image hydrate: Interactive image dihydrate: Interactive image trihydrate: Interactive image
ChemSpider	4896052
ECHA InfoCard	100.033.532
EC Number	236-901-2 hydrate: 693-463-9
PubChem CID	6365242 hydrate: 16217374
CompTox Dashboard (EPA)	DTXSID80928975 hydrate: DTXSID20584352
InChI InChI=1S/Eu.H3O4P/c;1-5(2,3)4/h;(H3,1,2,3,4)/p-3 Key: VTZYNNDLDPSINP-UHFFFAOYSA-K hydrate: InChI=1S/Eu.H3O4P.H2O/c;1-5(2,3)4;/h;(H3,1,2,3,4);1H2/q+3;;/p-3 Key: BOCFVANIXFYKBV-UHFFFAOYSA-K
SMILES [O-]P(=O)I([O-])[O-].[Eu+3] hydrate: [O-]P(=O)I([O-])[O-].[Eu+3].O dihydrate: [O-]P(=O)I([O-])[O-].[Eu+3].O.O trihydrate: [O-]P(=O)I([O-])[O-].[Eu+3].O.O.O
Properties
Chemical formula	EuO4P
Molar mass	246.934 g·mol−1
Appearance	colourless solid[1]
Density	5.81 g·cm−3[2]
Melting point	2,200 °C (3,990 °F; 2,470 K)[3]
Solubility in water	insoluble[4]
Structure[2]
Crystal structure	Monazite
Space group	P21/n (No. 14)
Lattice constant	a = 668.13(10), b = 686.18(9), c =  634.91(8) pm α = 90°, β =  103.96(1)°, γ = 90°
Thermochemistry
Heat capacity (C)	111.5 J/mol·K[5][6]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Preparation

Europium phosphate can be produced by the sol-gel method of europium(III) oxide. First, europium(III) oxide was dissolved in an equimolar amount of nitric acid, and then an excess of 10% phosphoric acid was added. The process also requires the addition of ammonia to adjust the pH to 4 and form a gel, which is then washed with water and heated to 1200 °C for a day.^[5][6]

Properties

Europium(III) phosphate is isotypic to CePO₄ and crystallizes in the monazite structure type, in the space group P2₁/n (no. 14, position 2) with the lattice parameters a = 668.13(10), b = 686.18(9), c = 634.91(8) pm and β = 103.96(1)° with four formula units per unit cell.^[2] Its heat capacity is 111.5 J·K⁻¹·mol⁻¹ at 298.15 K,^[5][6] and its bulk modulus is 159(2) GPa.^[8]