Capture of negative muons in chromium oxides

Muonic x-ray intensities of the Lyman series in oxygen and of the Lyman and Balmer series in chromium have been measured in CrO3 and in crystalline and amorphous Cr2O3. By means of muon cascade calculations which reproduce the measured intensities, angular momentum distributions of the captured muons have been determined for oxygen in a μ atomic level n=14 and for chromium in n=17. The Cr/O capture ratios per atoms have been found to be 3.23 in CrO3 and 2.64 in both structures of Cr2O3. This difference is due to the electronic bond structures. The capture probability in chromium is larger in the higher oxidation state which is in contrast to observations in some other elements. (author)