Virginia TechMaier, B. J.Welsch, A. M.Mihailova, B.Angel, R. J.Zhao, J.Paulmann, C.Engel, J. M.Marshall, W. G.Gospodinov, M.Petrova, D.Bismayer, U.2014-02-112014-02-112011-04-07Maier, B. J. ; Welsch, A. -M. ; Mihailova, B. ; et al., Apr 7, 2011. "Effect of La doping on the ferroic order in Pb-based perovskite-type relaxor ferroelectrics," PHYSICAL REVIEW B 83(13): 134106. DOI: 10.1103/PhysRevB.83.1341061098-0121http://hdl.handle.net/10919/25369The structural alteration induced by the substitution of three-valent cations with an isotropic electronic outermost shell for Pb2+ in perovskite-type relaxors was investigated in the solid solutions Pb1-xLaxSc(1+x)/2Ta(1-x)/2O3, x = 0.08 (PST-La) and Pb1-xLaxSc(1+x)/2Nb(1-x)/2O3, x = 0.23 (PSN-La). In order to distinguish the "charge" effects from "strain" effects associated with the incorporation of La3+ in the structure, Sr-containing PbSc0.5Nb0.5O3 was characterized as well. The structure of the compounds was analyzed by in situ Raman spectroscopy, single-crystal x-ray diffraction, and powder neutron diffraction at different temperatures or pressures. It is shown that the embedding of La3+ strongly affects the ferroic structural species due to strain effects through a disturbance of the system of lone-pair electrons associated with Pb2+ and a decrease in the tolerance factor. La doping suppresses the dynamical coupling between off-centered Pb and B-site cations and enhances antiphase BO6 octahedral tilting which, depending on the level of doping, may lead to long-range order of antiphase BO6 tilts at ambient conditions and frustrated antiferroelectric order of Pb ions at low temperatures.en-USIn Copyrighthigh-pressuredisorderPhysicsArticle - Refereedhttp://link.aps.org/doi/10.1103/PhysRevB.83.134106https://doi.org/10.1103/PhysRevB.83.134106