Substituent effects on the mechanical quality factor of Pb(Mg1/3Nb2/3)O3–PbTiO3 and Pb(Sc1/2Nb1/2)O3–PbTiO3 ceramics

The mechanical quality factor of Pb(Mg1/3Nb2/3)O3–PbTiO3(PMN–PT) and Pb(Sc1/2Nb1/2)O3–PbTiO3(PSN–PT) ceramics have been investigated for compositions close to the morphotropic phase boundary. Investigations were performed for various types of lower valent substituents on the B-site cation. These investigations have shown significant differences between the modified PMN–PT and PSN–PT crystalline solutions. In PMN–PT, lower valent substitutents had little effect upon the mechanical quality factor; however in PSN–PT it was found to be significantly increased. A crystal chemical approach is then used to explain these differences.