78236 20191122145056.0 doi 10.1016/j.jssc.2017.09.029 sideral 101847 ART-2018-101847 eng Ottini, Riccardo Local environments and transport properties of heavily doped strontium barium niobates Sr0.5Ba0.5Nb2O6 2018 Access copy available to the general public Unrestricted Undoped as well as K-doped (40%), Y-doped (40%), Zr-doped (10%), and Mo-doped (12.5%) strontium barium niobate Sr0.5Ba0.5Nb2O6 (SBN50) materials have been investigated to explore the effect of heavy doping on the structural and functional properties (thermo-power, thermal and electrical conductivities) both in the as prepared (oxidized) and reduced states. For all materials, the EXAFS spectra at the Nb – K edge can be consistently analyzed with the same model of six shells around the Nb sites. Doping mostly gives a simple size effect on the structural parameters, but doping on the Nb sites weakens the Nb–O bond regardless of dopant size and charge. Shell sizes and Debye–Waller factors are almost unaffected by temperature and oxidation state, and the disorder is of static nature. The functional effects of heavy doping do not agree with a simple model of hole or electron injection by aliovalent substitutions on a large band gap semiconductor. With respect to the undoped samples, doping with Mo depresses the thermal conductivity by ~ 30%, Y doping enhances the electrical conductivity by an order of magnitude, while Zr doping increases the Seebeck coefficient by a factor of 2–3. Globally, the ZT efficiency factor of the K-, Y-, and Zr-doped samples is enhanced at least by one order of magnitude with respect to the undoped or Mo-doped materials. info:eu-repo/semantics/openAccess by-nc-nd http://creativecommons.org/licenses/by-nc-nd/3.0/es/ 2.291 2018 CHEMISTRY, INORGANIC & NUCLEAR 18 / 45 = 0.4 2018 Q2 T2 CHEMISTRY, PHYSICAL 81 / 148 = 0.547 2018 Q3 T2 0.594 2018 Ceramics and Composites 2018 Q2 Condensed Matter Physics 2018 Q2 Physical and Theoretical Chemistry 2018 Q2 Inorganic Chemistry 2018 Q2 Materials Chemistry 2018 Q2 Electronic, Optical and Magnetic Materials 2018 Q2 info:eu-repo/semantics/article info:eu-repo/semantics/acceptedVersion Tealdi, Cristina Tomasi, Corrado Tredici, Ilenia G. Soffientini, Alessandro (orcid)0000-0003-2962-9251 Burriel, Ramón Universidad de Zaragoza (orcid)0000-0003-3567-7030 Palacios, Elías Universidad de Zaragoza (orcid)0000-0002-9687-4903 Castro, Miguel Universidad de Zaragoza Anselmi-Tamburini, Umberto Ghigna, Paolo Spinolo, Giorgio 2003 395 Universidad de Zaragoza Dpto. Física Materia Condensa. Área Física Materia Condensada 5001 065 Universidad de Zaragoza Dpto. Ciencia Tecnol.Mater.Fl. Área Cienc.Mater. Ingen.Metal. 258 (2018), 99-107 J. solid state chem. JOURNAL OF SOLID STATE CHEMISTRY 0022-4596 1000825 http://zaguan.unizar.es/record/78236/files/texto_completo.pdf Postprint 61093 http://zaguan.unizar.es/record/78236/files/texto_completo.jpg?subformat=icon icon Postprint oai:zaguan.unizar.es:78236 articulos driver 2019-11-22-14:45:49 ARTICLE