Electrical Properties and Site Distribution of Cations in (Mn y Co 1‐y ) 0.4 Fe 2.6 O 4

The high‐temperature electrical properties (conductivity and thermopower) of the Co 0.4 Fe 2.6 O 4 ‐Mn 0.4 Fe 2.6 O 4 join were measured in order to determine the cation intersite distribution and establish the conduction mechanism. The cobalt and manganese site occupancies show a nearly linear composition dependence. Trivalent iron occupancies reflect the transition from an octahedral substituent (Co) to a tetrahedral substituent (Mn), but any influence on the iron distribution reaction is minimal. Small polaron conduction parameters are similar to those for magnetite and vary little across the join.