INTERFACIAL DIELECTRIC LOSSES IN CO-DOPED NI-ZN FERRITES

The temperature and frequency dependence of tg delta and epsilon' for Ni0.8Zn0.2CoxFe2-x ferrites was studied in the 10(2)-10(6) Hz frequenc y range and 20-200 degrees C temperature range. The experimental curve s exhibit aspects very dependent of composition. To verify that interf acial losses, expected to appear in this type of system are compatible with the experimental results a calculation of the dielectric permitt ivity and dielectric loss using the Koops' model was made. A good corr elation between calculated and experimental curves was found.