Europium(III) phosphate is one of the phosphates of europium, with the chemical formula of EuPO<sub>4</sub>. Other phosphates include europium(II) phosphate (Eu<sub>3</sub>(PO<sub>4</sub>)<sub>2</sub>) and europium(II,III) phosphate (Eu<sub>3</sub>Eu(PO<sub>4</sub>)<sub>3</sub>).
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 ðC for a day.
Europium(III) phosphate is isotypic to CePO<sub>4</sub> and crystallizes in the monazite structure type, in the space group P2<sub>1</sub>/n (no. 14, position 2) with the lattice parameters a = 668.13(10), b = 686.18(9), c = 634.91(8) pm and ò = 103.96(1)ð with four formula units per unit cell. Its heat capacity is 111.5 J÷K<sup>âÂÂ1</sup>÷mol<sup>âÂÂ1</sup> at 298.15 K, and its bulk modulus is 159(2) GPa.