Standard X-ray Diffraction Powder Patterns

Europium Arsenate, EuAsO4 (tetragonal)Powder data cards. None.Additional published patterns. None.NBS sample. The sample of europium arsenatewas prepared at NBS from a water solution ofarsenic pentoxide and europium trichloride. Itwas dried at 110 °C. Spectrographic analysisshowed the following major impurities: 0.01 to0.1 percent each of antimony and silicon; 0.001to 0.01 percent each of aluminum, calcium, iron,magnesium, and titanium.The sample was colorless. The indices ofrefraction could not be determined because thesample was too fine.The d-values of the three strongest lines are:3.578, 2.704, and 1.8467 AStructural data. No reference to the structureof europium arsenate was found but it is apparently isostructural with yttrium arsenatewith the space group Dl£-I4i/amd (No. 141)and 4(EuAsO 4) per unit cell.Lattice Constants1963 National Bureau ofStandards at 25 °C.aA7. 1541± . 0004cA6. 3953±. 0004The density of europium arsenate calculatedfrom the NBS lattice constants is 5.902 g/cm3at 25 °C.hkl101200112220202301103321312400420332204224512440600, 404532424116444316604624Internal Standard,Tungsten, a = 3. 1648 ACo, 1.7889 A at 25 Cd0A4 773. 5782. 7042. 5302. 3862. 2362. 04301. 89531. 84671. 78861. 59971. 49141. 45951. 35111. 28471. 26461. 19211. 14551. 13081. 04280. 9919. 9643. 9557. 9233/210063175535451211128883781055113632