Influence of structural defects on the electrical properties of α-Fe2O3 ceramics

The electrical properties of alpha-Fe2O3 ceramics depend strongly upon the nature of the precursor and on the sintering conditions. The ceramics obtained from fresh precursors are characterised by the presence of extended defects, which tend to order as the sintering goes on. The p-type conductivity of those ceramics is mainly due to the presence of cationic impurities. The appearance of localised defects occurs during the sintering period of aged precursors. As these defects are associated to donor states, a predominant n-type conductivity is observed in the corresponding ceramics. 14 refs.