A comparison study has been made between the cubic monoxides and oxide spinels of iron, manganese, and cobalt in terms of cation defect structures and electrical properties. Although all six oxides share close-packed oxygen sublattices and have similar point-defect structures, there are considerable differences between conduction processes. Whether or not an octahedral/tetrahedral cation exchange reaction occurs may play a central role in governing conduction. In the iron oxides, n-type small polaron conduction takes place with small hopping energies (0. 11-0. 16 eV) between octahedral Fe**2** plus and Fe**3** plus , with the cation intersite reaction playing a dominant role. Very different behaviors are observed in the spinels and monoxides of manganese and cobalt. Intersite exchange is highly unlikely in these materials. Instead, disproportionation on the octahedral sites results in p-type small polaron conduction with larger hopping energies (0. 25, 0. 79 eV) between octahedral M**4** plus and M**3** plus in the spinels of cobalt and manganese.
|Original language||English (US)|
|Number of pages||7|
|Journal||Physica B: Physics of Condensed Matter & C: Atomic, Molecular and Plasma Physics, Optics|
|State||Published - May 1 1987|
|Event||Proc of the Int Conf on Electr Struct and Phase Stab in Adv Ceram - Argonne, IL, USA|
Duration: Aug 17 1987 → Aug 19 1987
ASJC Scopus subject areas