Standard X-ray Diffraction Powder Patterns

Bismuth Orthophosphate, BiPO4 (trigonal)Powder data cards. None.Additional published patterns. None.NBS sample. The sample of trigonal bismuthorthophosphate was precipitated at NBS from amixture of bismuth nitrate and phosphoric acid,Spectrographic analysis showed the following major impurities: 0.01 to 0.1 percent sodium and 0.001to 0.01 percent silicon.The sample was colorless. The indices of refraction could not be determined because the samplewas too fine.The d-values of the three strongest lines are:4.421, 3.025, and 2.8541.Structural data. Mooney-Slater [1] in 1962 determined the structure of the trigonal bismuthorthophosphate; it has the space group D|-P3i21(No. 152) and 3 (BiPO4) per unit cell This formis transformed to a monoclinic monazite structureat 350 C and to another higher temperaturemonoclinic form above 700 C.19621963Lattice constantsMooney-Slater [!]____National Bureau ofStandards at 25 C_aA6. 9666. 98200. 0004c&6. 4606. 47640. 0007The density of trigonal bismuth orthophosphatecalculated from NBS lattice constants is 5.538g/cm 3 at 25 C.Reference[1] R.C.L. Mooney-Slater, Polymorphic forms of bismuthphosphate, Z. Krist. 117, 371-385 (1962).hkl100101110111200102112210202211103300301212113203220302310311213104222400312114402321214322105304403412501330331420502215413, 421510422511Internal Standard,Tungsten, o=3.1648 ACu, 1.5405 A at 25 CdA6. 064. 4213.4943.0733. 0252.8542. 3752.2862. 2112. 1562. 0322. 0161. 9251. 8671.8371. 75711. 74521. 71151. 67741. 62391. 56931. 56441. 53681. 51181. 48921. 46871. 36981. 35631. 32061. 27501. 26671. 26241. 23841. 22171. 18851. 16391. 14501. 14251. 13281. 12671. 12551. 08601. 07741. 0709/6510043449482321256164225162416201211611551210314151057255834575432728-345 O—64———313