Influence of Cation Order on the Dielectric Properties of Pb(Mg1/3Nb2/3)O3-Pb(Sc1/2Nb1/2)O3 (PMN-PSN) Relaxor Ferroelectrics

The effect of the B-site cation chemistry and ordering on the dielectric properties of solid solutions in the (1-x)Pb(Mg1/3Nb2/3)O3-Pb(Sc1/2Nb1/2)O3 (PMN-PSN) perovskite system was examined in samples with 0.1 ≤ x ≤ 0.9. Thermal annealing treatments were effective in inducing long-range B-site order in the samples within this compositional range. The well-ordered, large chemical domain ceramics exhibit relaxor behavior up to x = ~0.5; for higher values of x, normal ferroelectric behavior was observed. For x ≤ 0.5 reductions in the chemical domain, size had no significant effect on the weak-field dielectric properties, but induced a transition to relaxor behavior for x > ~0.6. The disordered PSN-rich samples undergo a spontaneous zero-field relaxor to ferroelectric transition similar to that reported previously for PSN. The field-dependent properties of compositions lying closest to the relaxor to ferroelectric crossover exhibited the highest sensitivity to alterations in the chemical order. The properties of this system are consistent with a "random site" description of the 1:1 ordered Pb(β′1/2 β1/2)O3 structure with β′ = (Mg(2-2x)/3Nb(1-x)/3Scx) and β′′ = Nb. Comments Copyright The American Ceramic Society. Reprinted from Journal of the American Ceramic Society, Volume 86, Issue 11, November 2003, pages 1861-1866. This journal article is available at ScholarlyCommons: http://repository.upenn.edu/mse_papers/44 Influence of Cation Order on the Dielectric Properties of Pb(Mg1/3Nb2/3)O3–Pb(Sc1/2Nb1/2)O3 (PMN-PSN) Relaxor Ferroelectrics Leon Farber and Peter Davies* Department of Materials Science and Engineering, University of Pennsylvania, 3231 Walnut St., Philadelphia, Pennsylvania 19104-6272 The effect of the B-site cation chemistry and ordering on the dielectric properties of solid solutions in the (1 x)Pb(Mg1/3 Nb2/3)O3–Pb(Sc1/2Nb1/2)O3 (PMN-PSN) perovskite system was examined in samples with 0.1 < x < 0.9. Thermal annealing treatments were effective in inducing long-range B-site order in the samples within this compositional range. The wellordered, large chemical domain ceramics exhibit relaxor behavior up to x 0.5; for higher values of x, normal ferroelectric behavior was observed. For x < 0.5 reductions in the chemical domain, size had no significant effect on the weak-field dielectric properties, but induced a transition to relaxor behavior for x > 0.6. The disordered PSN-rich samples undergo a spontaneous zero-field relaxor to ferroelectric transition similar to that reported previously for PSN. The field-dependent properties of compositions lying closest to the relaxor to ferroelectric crossover exhibited the highest sensitivity to alterations in the chemical order. The properties of this system are consistent with a “random site” description of the 1:1 ordered Pb( 1/2 1/2)O3 structure with (Mg(2 2x)/3 Nb(1 x)/3Scx) and Nb.