Abstract
SMALL thin red needles, heavily striated down the prism, were prepared by adding concentrated sulphuric acid to a cold concentrated solution of potassium dichromate. The crystals were sealed up separately in thin glass tubes to prevent deliquescence. Measurements on an ionisation spectrometer and from oscillation photographs gave the value of the cell size as a = 8.50 A., b = 4.73 A., c = 5.72 A., the probable error being not greater than ± 1 per cent. The density given by Groth is 2.73–2.82 and there are therefore 4 molecules per cell. The axial ratios given by Nordenskjöldl are a: b: c = 1: 0.69: 0.63. The relation between his ratios and ours is a: b: c (Wooster) = a: 3/4;b: c (Nordenskjöld). The only face from which he could obtain the ratio a: b should have been indexed (230) instead of (120). All the specimens which we have examined up to the present are mimetic twins on (110), closely simulating hexagonal symmetry.
Similar content being viewed by others
Article PDF
References
A. E. Nordenskjöld, Pogg. Ann. Phy. u. Chem., 114, 622; 1861.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
WOOSTER, W., WOOSTER, N. Crystal Structure of Chromium Trioxide. Nature 127, 782 (1931). https://doi.org/10.1038/127782b0
Issue Date:
DOI: https://doi.org/10.1038/127782b0
This article is cited by
-
Subsolidus phase equilibria in the system AlVO4−MoO3
Journal of Thermal Analysis (1995)
Comments
By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.