Europium(III) phosphate explained

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).^[1]

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.^{[2] [3]}

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.^[4]

Notes and References

1. Grunwald . Waldemar . Wittich . Knut . Glaum . Robert . Anhydrous Europium Phosphates: A Comprehensive Report on Syntheses, Crystal Structures, and Phase Relations . Zeitschrift für anorganische und allgemeine Chemie . Wiley . 644 . 22 . 2018-08-06 . 0044-2313 . 10.1002/zaac.201800193 . 1403–1414. 104565178 .
2. Popa . K. . Konings . R.J.M. . High-temperature heat capacities of EuPO₄ and SmPO₄ synthetic monazites . Thermochimica Acta . Elsevier BV . 445 . 1 . 2006 . 0040-6031 . 10.1016/j.tca.2006.03.023 . 49–52.
3. Gavrichev . K. S. . Ryumin . M. A. . Tyurin . A. V. . Gurevich . V. M. . Komissarova . L. N. . The heat capacity and thermodynamic functions of EuPO₄ over the temperature range 0–1600 K . Russian Journal of Physical Chemistry A . Pleiades Publishing Ltd . 83 . 6 . 2009 . 0036-0244 . 10.1134/s0036024409060053 . 901–906. 2009RJPCA..83..901G . 98200684 .
4. Lacomba-Perales . R. . Errandonea . D. . Meng . Y. . Bettinelli . M. . 2010-02-24 . 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 . Physical Review B . en . 81 . 6 . 064113 . 10.1103/PhysRevB.81.064113 . 1098-0121. 0911.5669 . 119249866 .