The Effect of Mechanical Activation on the Structure and Dielectric Properties of PbYb 1/2 Nb 1/2 O 3 –PbFe 1/2 Nb 1/2 O 3 Solid Solution Ceramics

Recently we have found out that high-energy mechanical activation during mechanochemical synthesis stimulates disordering of Yb3+ and Nb5+ cations in the PbYb1/2Nb1/2O3 (PYN) ceramics. However, one could expect a contamination of thus obtained ceramics by iron as the planetary mill AGO-2 with both jars and balls made of the stainless steel was used for mechanical activation. To elucidate the effect of iron doping on the compositional ordering of PYN, in the present work several (1 − x)PYN–xPbFe1/2Nb1/2O3 (PYN–xPFN) solid solution compositions have been fabricated by both the usual solid-state synthesis and by high-energy mechanochemical synthesis and their structure and properties were compared. Basing on these data the (x, T)-phase diagrams for the PYN – xPFN solid solutions fabricated by both methods were constructed. It was found out that the difference in the lattice parameters values and dielectric properties of ceramics fabricated by different methods are partially due to the formation of the (1–x)PYN–xPFN solid solutions with PFN content larger than nominal one and partially due to the effect of high-energy mechanical activation.