Two Synthetic Compounds Containing Chromium in Different Valency States

W. Johnson
The United Steel Companies Limited, Research and Development Dept., Swinden Laboratories, Moorgate, Rotherham, Yorkshire.

Summary: Two compounds, one an apatite and the other a perovskite, have been synthesized by sintering mixtures containing CaO and Cr2O3, and CaO, Cr2O3, and Fe2O3 respectively. The apatite formed by partial oxidation of the Cr2O3 and subsequent pick-up of moisture from the atmosphere, to give Ca5(CrO4)3OH. The perov-skite formed as a non-stoicheiometric compound Ca4(Fe,Cr)4O11 by partial oxidation of the Cr2O3 during firing. Lattice parameters and interplanar spacings are given for the two structures.

Mineralogical Magazine; March 1960 v. 32; no. 248; p. 408-411; DOI: 10.1180/minmag.1960.032.248.07
© 1960, The Mineralogical Society
Mineralogical Society (