| Abstract | A seriesofpolycrystallineM-typehexagonalferriteswiththecompositionSr0.5Ca0.5CoxTixFe122xO19
(where x¼0.0–0.8)werepreparedbytheconventionalceramictechnique.Theelectricalconductivity
has beenmeasuredfrom300to590K.Thedcconductivity, sdc, exhibitedasemiconductorbehavior.
The negativesignofthermoelectricpowercoefficient S reveals thatallsamplesaren-typesemi-
conductors.Both sdc and mobility, md, increaseswiththesubstitutionofCo2? and Ti4? ions, reach
maximumat x¼0.4 andstartdecreasingat x40.4. Manyconductionmechanismswerediscussedto
explain theelectricconductioninthesystem.Itwasfoundthatthehoppingconductionisthe
predominantconductionmechanism.Forsampleswithcompositionalparameter x¼0.0 and0.8,the
band conductionmechanismsharesinelectricconductionbesidethehoppingprocess |