Synthesis of Potassium Manganese Oxides under Hydrothermal Conditions

T. Endo, S. Kume, M. Shimada and M. Koizumi
College of General Education, Osaka University
Institute of Scientific and Industrial Research, Osaka University

Summary: A 1 M solution of potassium permanganate was sealed in a gold capsule and was treated under conditions of temperature and pressure up to 800 °C and 2·5 kb. Different kinds of products were produced under different conditions of synthesis, and potassium manganate, birnessite, cryptomelane, hausmannite, manganosite, and a new phase appeared. The chemical composition of the new phase was determined as K2Mn4O9 and its X-ray powder diffraction pattern was indexed on a hexagonal cell with a 11·295 and c 21·870 Å.

Mineralogical Magazine; March 1974 v. 39; no. 305; p. 559-563; DOI: 10.1180/minmag.1974.039.305.08
© 1974, The Mineralogical Society
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