Acta Crystallographica Section B

Volume 65, Part 1 (February 2009)

research papers

 

Polymorphism of K₂Co₂Mo₃O₁₂: variations in the packing schemes and changes in molybdenum coordination under high pressure

J. M. Engel, H. Ahsbahs, H. Fuess and H. Ehrenberg

Abstract: Within systematic studies on the K-Co-Mo-O system so-called high-temperature and high-pressure modifications of K₂Co₂Mo₃O₁₂ were found. The Birch-Murnaghan fits for the ambient-conditions modification (Z = 4) and the high-pressure phase II (Z = 8) lead to V₀ = 1193.09 (4) Å³, K = 30.8 (8) GPa, = 5.4 (4) and V₀ = 2170 (10) Å³, K = 51 (2) GPa with fixed at 4.0, respectively. The high-pressure phase transition is denoted as pseudoreconstructive [Wiesmann et al. (1997). J. Solid State Chem. 132, 88-97], because some [MoO₄] tetrahedra turn into edge-sharing pairs of [MoO₅] pyramids or face-sharing pairs of [MoO₆] octahedra. The new phases are presented and compared with the phase.

Keywords: polymorphism; packing schemes; materials science.

	Structure factor file (CIF format) (119.7 kbytes) [ doi:10.1107/S0108768108038536/sn5075alphasup2.fcf ] Contains datablock alpha
	Structure factor file (CIF format) (148.5 kbytes) [ doi:10.1107/S0108768108038536/sn5075betasup3.fcf ] Contains datablock beta
	Structure factor file (CIF format) (57.1 kbytes) [ doi:10.1107/S0108768108038536/sn5075IIsup4.fcf ] Contains datablock II

To open or display or play some files, you may need to set your browser up to use the appropriate software. See the full list of file types for an explanation of the different file types and their related mime types and, where available links to sites from where the appropriate software may be obtained.

The download button will force most browsers to prompt for a file name to store the data on your hard disk.

Where possible, images are represented by thumbnails.

Copyright © International Union of Crystallography
IUCr Webmaster