THE AC ELECTRICAL-CONDUCTIVITY FOR CO-SUBSTITUTED SBNI FERRITES

The real ac electrical conductivity sigma(ac)' has been studied for th e ferrite system CoxNi5/3-xSb1/3Fe1O4 as a function of frequency, temp erature and composition. The experimental results indicate that sigma( ac)' increases with increasing frequency, temperature and Co ion conte nt. sigma(ac)' becomes frequency independent at higher temperatures. T he activation energies for electrical conduction and the Curie tempera tures decrease with increasing Co ion content. The activation energy f or electrical conduction in the ferrimagnetic region decreases as freq uency increases. In the power law for ac electrical conductivity (sigm a(2)(omega)=B omega(n)), the constant B increases, while the power n o f the frequency decreases with increasing Co ion substitution and temp erature. An empirical formula for the temperature dependence of n is s uggested.