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).

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.

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.