دراسة الخواص الكهربائية و البنية الدقيقة للجملة SnO2-Co3O4-Nb2O5 ذات المقاومة المتغيرة عند إشابتها بأكسيد اللانثنيوم

الملخص EN

SnO2-Co3O4-Nb2O5-La2O3 varistor samples were prepared using standard ceramic technique by adding a definite rates of Co3O4 and Nb2O5 to SnO2 with different percentages of La2O3 from 0.050 to 0.200.

It found that the addition of La2O3 decreases the samples density, and it showed no change in the phase structure of the samples.

Also the addition of La2O3 to the samples decreased their average grain size.

The electrical properties of the samples at different temperatures (10, 30, 60, 90, 120oC) had studied.

It was found that the all samples had varistor behavior.

It also showed that, the breakdown electric field ( Er) and non-linear coefficient (a) were depended on the temperatures and the Lanthanum oxide concentration of the system.

It had found that the best values of a and Er appeared at the concentration of 0.050 La2O3.