Structural and Dielectric Studies of PbYb_(1/2)Nb_(1/2)O_3 Ceramics with the Differing Degree of the Long-Range Compositional Ordering Fabricated by Mechanoactivation

摘要

It was found out that compositional ordering degree S of Yb~(3+) and Nb~(5+) ions in PbYb1/2Nb1/2O3 ceramics and correspondingly both the temperature and diffusion of antiferroelectric phase transition can be varied within a wide range by means of high-energy mechanical activation. In particular, for the first time disordered PbYb1/2Nb1/2O3 ceramics exhibiting relaxor-like dielectric properties was fabricated without the use of any additives. For the most ordered PbYb1/2Nb1/2O3 samples (S≈0.82), the coexistence of cubic paraelectric and orthorhombic anti-ferroelectric phases in a temperature range 190-300 °C was revealed.