Tin doping of α-Cr_2O_3 and α-(FeCr)_2O_3

摘要

Tin-doped oxides of the type α-Cr_2O_3 and α-(FeCr)_2O_3 have been prepared. Tin K-edge EXAFS indicates tin to be octahedrally coordinated in all materials. ~(119)Sn and ~(57)Fe Moessbauer spectra recorded from the corundum-related ca. 7% tin-doped α-Cr_2O_3 and α-Fe_(1.1)Cr_(0.9)O_3 phases show the presence of magnetic order from ca. 20 to ca. 220 K in the case of α-Cr_2O_3 and to 295 K in the case of α-Fe_(1.1)Cr_(0.9)O_3. The ~(119)Sn Moessbauer spectra demonstrate weaker superexchange interactions between Sn~(4+) and Cr~(3+) as compared to those between Sn~(4+) and Fe~(3+).