THE ELECTRICAL-PROPERTIES OF GE4+ SUBSTITUTED COPPER FERRITE

The electrical resistivity (rho) and thermoelectric power (alpha) were measured in the temperature range from 300 K to 750 K on the system Cu1+xGexFe2-2xO4 with x = 0.05, 0.1, 0.15, 0.2 and 0.3. The dependence of electrical properties with temperature showed three regions. In the first region the conduction is due to impurities whereas in the second and third it is due to polaron hopping. The temperature dependence of alpha and rho suggests that the transport properties measured may be interpreted on the basis of polaron hopping. The activation energy in paramagnetic region is found to be less than that in ferrimagnetic region. This behaviour therefore can be stated to be anomalous.