Abstract
Ceramics of Li0.98-x Ta1.004-x/5 O3 solid solutions with 0 ≤ × ≤ 0.20 are studied by a new theoretical approach. From the experience, we have proposed the new vacancy models which are able to describe substitutional mechanism in Ni-doped lithium tantalate. Theoretical approach combined with generalised vacancy models allows us to establish a new expression of electrical conductivity which takes into account the defect structure of Ni-doped lithium tantalate. Calculation of the Curie temperature in Ni-doped non stoichiometric lithium tantalate reveals good correspondence with experimental results.
Acknowledgments
We gratefully acknowledge financial support from the Ministry of Higher Education and the National Center for Scientific Research and Technology.