caa a22 4500 463213793 CHVBK 20180405153150.0 cr unu---uuuuu 170326e20071101xx s 000 0 eng 10.1007/s00339-007-4096-4 doi (NATIONALLICENCE)springer-10.1007/s00339-007-4096-4 Grain-bulk versus grain-boundary sensitivities to redox reaction in yttria-doped ceria ceramics viewed from impedance spectroscopy [Elektronische Daten] [J.-C. M'Peko, M.F. De Souza, C.L. Da Silva, D.P.F. De Souza] Yttria-doped ceria ceramics were prepared and reduced in an oxygen-deficient (argon) ambient. Electrical characterization through impedance spectroscopy revealed ionic-type conduction processes in as-sintered samples, with grain-bulk and grain-boundary activation energies (H) of about 1.00eV and 1.05eV, respectively. Electrical results from the reduced materials showed a predominant electronic-type, relatively high conductivity for the grains (H=0.52eV), in contrast to a still ionic-like, relatively poor conductivity for the grain boundaries (H=0.95eV). With the support of the results processed after re-oxidizing the materials in air combined with information from literature, this apparently contradictory behavior is discussed in terms of electron trapping at (Ce3+: $V_{\text{O}^{..}}$ )-type defect complexes. The overall work strongly supports the idea that surfaces (e.g., grain boundaries) in polycrystalline ceria are indeed much more sensitive to redox interactions than lattice. Springer-Verlag, 2007 M'Peko J.-C Instituto de Física de São Carlos (IFSC), Universidade de São Paulo (USP), C. Postal 369, CEP 13560-970, São Carlos, SP, Brazil aut De Souza M.F. Instituto de Física de São Carlos (IFSC), Universidade de São Paulo (USP), C. Postal 369, CEP 13560-970, São Carlos, SP, Brazil aut Da Silva C.L. Departamento de Engenharia de Materiais (DEMa), Universidade Federal de São Carlos (UFSCar), C. Postal 676, CEP 13565-905, São Carlos, SP, Brazil aut De Souza D.P.F. Departamento de Engenharia de Materiais (DEMa), Universidade Federal de São Carlos (UFSCar), C. Postal 676, CEP 13565-905, São Carlos, SP, Brazil aut Applied Physics A Springer-Verlag 89/2(2007-11-01), 509-515 0947-8396 89:2<509 2007 89 339 https://doi.org/10.1007/s00339-007-4096-4 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00339-007-4096-4 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- M'Peko J.-C Instituto de Física de São Carlos (IFSC), Universidade de São Paulo (USP), C. Postal 369, CEP 13560-970, São Carlos, SP, Brazil aut NATIONALLICENCE 700 1- De Souza M.F. Instituto de Física de São Carlos (IFSC), Universidade de São Paulo (USP), C. Postal 369, CEP 13560-970, São Carlos, SP, Brazil aut NATIONALLICENCE 700 1- Da Silva C.L. Departamento de Engenharia de Materiais (DEMa), Universidade Federal de São Carlos (UFSCar), C. Postal 676, CEP 13565-905, São Carlos, SP, Brazil aut NATIONALLICENCE 700 1- De Souza D.P.F. Departamento de Engenharia de Materiais (DEMa), Universidade Federal de São Carlos (UFSCar), C. Postal 676, CEP 13565-905, São Carlos, SP, Brazil aut NATIONALLICENCE 773 0- Applied Physics A Springer-Verlag 89/2(2007-11-01), 509-515 0947-8396 89:2<509 2007 89 339 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer