Preparation and Investigation of BaSO4KMnO4 Crystals

BaSO4 crystals containing KMnO4 prepared by precipitation were investigated morphologically, chemically and by X-ray diffraction. The colour of the preparations is homogeneous and stable. The colour intensity and also the amount of dissolved KMnO4 (maximum approx. 30 Mol%) increases with concentration of KMnO4 in the reaction solution to a limiting value dependent on the temperature. The lattice constants or the unit cell volume of the BaSO4–KMnO4 crystals increase with the proportion of KMnO4. The experimental values agree well with the Vegard rule for preparations up to 18 Mol% KMnO4, but with higher proportions significant departures were observed. They may easily be explained by adsorpt…