Europium(III) phosphate
{{Chembox
|ImageFile=File:Eu3+.svgFile:Phosphat-Ion.svg
|Section1={{Chembox Identifiers
| index1_label=hydrate
| CASNo= 13537-10-5
| CASNo1 = 14913-20-3
| CASNo2=15259-63-9|CASNo2_Comment=semihydrate
| CASNo3=34377-51-0|index3_label=dihydrate
| CASNo4=49836-68-2|index4_label=trihydrate
| DTXSID1 = DTXSID20584352
| EC_number= 236-901-2
| EC_number1 = 693-463-9
| PubChem = 6365242
| PubChem1 = 16217374
| ChemSpiderID = 4896052
| StdInChI=1S/Eu.H3O4P/c;1-5(2,3)4/h;(H3,1,2,3,4)/p-3
| StdInChIKey = VTZYNNDLDPSINP-UHFFFAOYSA-K
| InChI1=1S/Eu.H3O4P.H2O/c;1-5(2,3)4;/h;(H3,1,2,3,4);1H2/q+3;;/p-3
| InChIKey1 = BOCFVANIXFYKBV-UHFFFAOYSA-K
| SMILES=[O-]P(=O)I([O-])[O-].[Eu+3]
| SMILES1=[O-]P(=O)I([O-])[O-].[Eu+3].O
| SMILES3=[O-]P(=O)I([O-])[O-].[Eu+3].O.O
| SMILES4=[O-]P(=O)I([O-])[O-].[Eu+3].O.O.O
}}
|Section2={{Chembox Properties
|Eu=1|P=1|O=4
| MeltingPtC= 2200
|BoilingPt=
}}
|Section3={{Chembox Structure
|CrystalStruct=Monazite
|SpaceGroup=P21/n (No. 14)
|LattConst_a=668.13(10)|LattConst_b=686.18(9)|LattConst_c= 634.91(8) pm|LattConst_beta= 103.96(1)
}}
|Section4={{Chembox Thermochemistry
}}
}}
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).{{cite journal | last1=Grunwald | first1=Waldemar | last2=Wittich | first2=Knut | last3=Glaum | first3=Robert | title=Anhydrous Europium Phosphates: A Comprehensive Report on Syntheses, Crystal Structures, and Phase Relations | journal=Zeitschrift für anorganische und allgemeine Chemie | publisher=Wiley | volume=644 | issue=22 | date=2018-08-06 | issn=0044-2313 | doi=10.1002/zaac.201800193 | pages=1403–1414| s2cid=104565178 }}
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.{{cite journal | last1=Popa | first1=K. | last2=Konings | first2=R.J.M. | title=High-temperature heat capacities of EuPO4 and SmPO4 synthetic monazites | journal=Thermochimica Acta | publisher=Elsevier BV | volume=445 | issue=1 | year=2006 | issn=0040-6031 | doi=10.1016/j.tca.2006.03.023 | pages=49–52}}{{cite journal | last1=Gavrichev | first1=K. S. | last2=Ryumin | first2=M. A. | last3=Tyurin | first3=A. V. | last4=Gurevich | first4=V. M. | last5=Komissarova | first5=L. N. | title=The heat capacity and thermodynamic functions of EuPO4 over the temperature range 0–1600 K | journal=Russian Journal of Physical Chemistry A | publisher=Pleiades Publishing Ltd | volume=83 | issue=6 | year=2009 | issn=0036-0244 | doi=10.1134/s0036024409060053 | pages=901–906| bibcode=2009RJPCA..83..901G | s2cid=98200684 }}
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. Its heat capacity is 111.5 J·K−1·mol−1 at 298.15 K, and its bulk modulus is 159(2) GPa.{{Cite journal |last1=Lacomba-Perales |first1=R. |last2=Errandonea |first2=D. |last3=Meng |first3=Y. |last4=Bettinelli |first4=M. |date=2010-02-24 |title=High-pressure stability and compressibility of A PO 4 ( A = La , Nd, Eu, Gd, Er, and Y) orthophosphates: An x-ray diffraction study using synchrotron radiation |url=https://link.aps.org/doi/10.1103/PhysRevB.81.064113 |journal=Physical Review B |language=en |volume=81 |issue=6 |page=064113 |doi=10.1103/PhysRevB.81.064113 |issn=1098-0121|arxiv=0911.5669 |s2cid=119249866 }}