Transformation processes in relaxor ferroelectric PbSc0.5Ta0.5O3 heavily doped with Nb and Sn
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Anna-Maria Welsch
Abstract
The effect of a third type of B-site cation on the temperature- and pressure-induced structural changes in ABO3-type relaxors has been studied by in-situ Raman scattering and X-ray diffraction on 0.72PbSc0.5Ta0.5O3—0.28PbSc0.5Nb0.5O3 (PSTN) and 0.78PbSc0.5Ta0.5O3—0.22PbSnO3 (PSTS). The incorporation of Nb into the PST matrix is an isovalent substitution for Ta5+ on the ferroelectrically active B-site, whereas the incorporation of Sn4+ is a coupled aliovalent substitution for both types of B-cations in the host system. Both PSTN and PSTS exhibit the characteristic temperature T*, which for PSTS is shifted to slightly lower temperatures. The incorporation of Nb and Sn into the PST matrix smears the transformation processes near and below T* and suppresses the ferroelectric long-range order at low temperatures. Both PSTN and PSTS exhibit a continuous pressure-induced phase transition. The high-pressure phases have the same structural features as for pure PST: suppressed B-cation off-centre shifts, enhancement of coupled Pb—O ferroic species, and long-range order of anti-phase tilts of the BO6 octahedra. Nb-doping shifts the critical pressure pc from 1.9 GPa for pure PST to 2.5 GPa, whereas Sn-doping lowers pc to 1.3 GPa. The incorporation of both Nb and Sn decreases the degree of the overall pressure-induced structural distortion, with the effect of Sn being more pronounced than Nb. The dilution of the B-site cation system with Sn4+ results in local electric and elastic fields which reduce the coherence between nanoregions with anti-phase octahedral tilting and shifts the pressure at which long-range order of the tilts occurs to ∼4 GPa.
© by Oldenbourg Wissenschaftsverlag, Hamburg, Germany
Articles in the same Issue
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- Spontaneous and induced surface piezoresponse in PbMg1/3Nb2/3O3 single crystals
- Diffuse scattering and local structure modeling in ferroelectrics
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- Temperature-dependent synchrotron powder diffraction phase studies of (K0.37Na0.52Li0.03)(Nb0.87Ta0.1Sb0.03)O3 ferroelectric ceramics
- Polar states of the impurity system KTaO3:Li
- Neutron total scattering studies on A-site disorder in lead-free ferroelectric Bi0.5(Na1–xKx)0.5TiO3
- In situ neutron diffraction study of electric field induced structural transitions in lanthanum doped lead zirconate titanate
- A brief review on the model antiferroelectric PbZrO3 perovskite-like material
- Broadband dielectric investigations of indium rich CuInP2S6 layered crystals
- Ferroelectricity and superconductivity: competing or cooperating phenomena
- A new computer tool at the Bilbao Crystallographic Server to detect and characterize pseudosymmetry
Articles in the same Issue
- Preface: Advanced Ferroelectrics: Structure and Properties
- Compositional disorder, polar nanoregions and dipole dynamics in Pb(Mg1/3Nb2/3)O3-based relaxor ferroelectrics
- Spontaneous and induced surface piezoresponse in PbMg1/3Nb2/3O3 single crystals
- Diffuse scattering and local structure modeling in ferroelectrics
- Transformation processes in relaxor ferroelectric PbSc0.5Ta0.5O3 heavily doped with Nb and Sn
- Temperature-dependent synchrotron powder diffraction phase studies of (K0.37Na0.52Li0.03)(Nb0.87Ta0.1Sb0.03)O3 ferroelectric ceramics
- Polar states of the impurity system KTaO3:Li
- Neutron total scattering studies on A-site disorder in lead-free ferroelectric Bi0.5(Na1–xKx)0.5TiO3
- In situ neutron diffraction study of electric field induced structural transitions in lanthanum doped lead zirconate titanate
- A brief review on the model antiferroelectric PbZrO3 perovskite-like material
- Broadband dielectric investigations of indium rich CuInP2S6 layered crystals
- Ferroelectricity and superconductivity: competing or cooperating phenomena
- A new computer tool at the Bilbao Crystallographic Server to detect and characterize pseudosymmetry
