Standard X-ray Diffraction Powder Patterns

Potassium Perchromate, K3CrO8 (tetragonal)Powder data cards. None.Additional published patterns. Wilson [1] 1941.NBS sample. The sample of ipotassium perchromate was obtained from City Chemical Corp.,New York, N.Y. Spectrographic analysis did notshow any impurities greater tnan the range 0.0001to 0.001 percent.The color of the sample was deep red. Theindices of refraction are N 0= 1.774 and N e — 1.730.It is optically negative.The d-values of the three strongest lines are:2.979, 2.372, and 1.856 LStructural data. Wilson [1] in 1941 determinedthat potassium perchromate has the space groupDiJ-l42m (No. 121) and 2(K3CrO 8 ) per unit cell.Potassium perchromate is used as a structure type.The unit cell measurements reported by Wilsonhave been converted from kX to angstrom unitsfor comparison with NBS values.19411963Lattice constantsWilson [1].__. ......National Bureau ofStandards at 25 °C.aA6. 716. 711cA7. 627. 641The density of potassium perchromate calculated from NBS lattice constants is 2.869 g/cm3at 25 °C.Reference[1] I. A. Wilson, X-ray analysis of potassium perchromate, K2Cr0 8 and isomorphous compounds, Arkiv.Kemi Minerali. Geol. B15, 1-7 (1941).hkl101110002200112211202220301310222004312321303, 400204330402420224332314413501404512116, 521440325600532316Internal Standard,Tungsten, a==3.1648 ACu, 1:5405 A at 25 Cd5.0544. 7493. 8223.3572. 9792. 7952. 5242.3722. 1472, 1212.0161. 9111.8561.8081. 6771. 6591. 58151. 53651. 50041. 48801. 46151. 41981. 37181. 32191. 26071. 24451. 22991. 18631. 18081. 11831. 10201. 0920/42181361001755352794775753101210