ESR study of Fe3+ and Mn2+ ions on trigonal sites in ilmenite structure MgTiO3 |
| |
Authors: | ELopez Carranza RT Cox |
| |
Institution: | Departamento de Física, Universidad Nacional de Ingeniería, Casilla 1301, Lima, Perú Peru;Section de Résonance Magnétique, Département de Recherche Fondamentale, CEN-Grenoble, 85X, 38041, Grenoble-Cedex, France |
| |
Abstract: | Electron spin resonance has been observed for Fe3+ and Mn2+ ions occupying sites with trigonal symmetry in undoped and doped Verneuil-grown crystals of the ilmenite type compound MgTiO3. At 300 K, the fine structure parameters in the spin Hamiltonian are (in 10?4cm?1) D = +844 (± 1), (a? F) = +118 (± 1), a = 69 (± 7) for Fe3+ and D = +164 (± 1), (a ? F) = +10.2 (± l), a = 7.0 (± 1) for Mn2+. These values are compared with literature data for Fe3+ and Mn2+ in other oxides, especially Al2o3, with particular reference to the recent “superposition” theory of the effect of a trigonal distortion. From the orientation of the axes of cubic pseudosymmetry of the spin Hamiltonian, and with the assumption that a has the same sign for both ions, it is proposed that Fe3+ and Mn2+ occupy the same octahedral site, namely the Mg2+ site. Anomalous line splittings observed for one sample were attributed to twinning on (0001) or {1120} planes. |
| |
Keywords: | |
本文献已被 ScienceDirect 等数据库收录! |
|