Abstract:
Magnetic and optical studies were made on chromium (III) chloride supported at various concentrations on a porous alumina, the impregnated samples having been calcined at different temperatures between 50–1150°C. The measurement of magnetic susceptibility and electron paramagnetic resonance spectra was carried out at controlled temperatures from –196 to 300°C. Optical reflectance spectra were obtained at room temperature on selected samples. The results suggest that clustering of the chromium chloride occurs, even in the lowest concentration studies (1.5 wt.% Cr); heat treatment in air leads to the formation of a mixed oxide phase containing CrVI, the stability of which is discussed in terms of electron transfer between the support and the chromium species.
