Abstract:
1. The literature is reviewed and discussed
2. Investigations show
(a) all preparations of the intermediate oxides by "wet methods or at temperatures below 250° give products with no X-ray diffraction patterns.
(b) an intermediate oxide of apparent composition CrO2.38 is formed on heating CrO3 between 260° - 380°C, X-ray data showed, that on heating, CrO2Cl2 and Cr(NO3)3 gave this oxide mixed with Cr2O3
(c) all other preparations gave the X-ray pattern of Cr2O3 or the "solid solution of oxygen in Cr203" of Michel and Benard