The conduction mechanism of Cu-Si ferrite

The mixed ferrite Cui, Six Fe(2-2x) O(4): with 0 <= x <= 0.3 in step of 0.05 were prepared by standard ceramic techniques. The X-ray analysis confirmed that the compositions are well formed in a single phase. The d.c. and ac. electrical conductivity as a function of temperature have been studied. The relation In a vs. T(-1) showed two regions with different slopes for all values of x except x = 0.0 showed one slope only. The two activation energies around a kink point called T(k), were calculated. The change of the slope at Tk was attributed to a change in the nature of type of conduction mechanism (i.e. from n-type to p-type). The activation energies were greater than 0.3 eV; which clearly suggested that the conduction is due to small polaron model. (C) 2010 Elsevier B.V. All rights reserved.