Samiha T. Bishay

Conductivity improvement of Li-Co-Yb ferrite

The effect of γ-irradiation on some physical properties of rare earth ferrite of the general formula Li0.5 + zCozYbxFe2.5-2z-xO4, (z = 0.1, x = 0.00, 0.025, 0.050,...,0.200) was discussed. The temperature dependence of the polarization and resistance was studied in the range (300 K≤T≤700 K) at different frequencies (10 kHz≤f≤1 MHz). The relaxation time and the activation energy were calculated for γ doses of 1 and 3 Mrad. Also, a comparison was made between the ac resistance, before and after irradiation, for the samples with different Yb concentrations (0.0≤x≤0.2). The results after irradiation with a 1 Mrad dose of γ-rays showed that the resistance at the critical concentration decreases from 800 to 25 kΩ, at room temperature. Furthermore, with increasing temperature the resistance ranged from R≈130 kΩ at T≈310 K to R≈0.13 kΩ at T≈640 K. Thus, it is possible to improve the conductivity of this type of rare earth ferrite material to be used in technological applications at room temperature as well as at high temperatures.