RT Journal Article
T1 Structures, phase fields, and mixed protonic−electronic conductivity of Ba-Deficient, Pr-Substituted BaZr0.7Ce0.2Y0.1O3−δ
A1 Heras Juaristi, Gemma
A1 Amador, Ulises
A1 Romero de Paz, Julio
A1 Fuentes, Rodolfo
A1 Chinelatto, Adilson
A1 Ritter, Clemens
A1 Fagg, Duncan
A1 Pérez Coll, Domingo
A1 Mather, Glenn
AB The BaZr0.7Ce0.2Y0.1O3−δ−BaPrO3−δ perovskite system, of interest for high-temperature electrochemical applications involving mixed protonic−electronic conductivity, forms a solidsolution with a wide interval of Ba substoichiometry in the range Ba(Ce0.2Zr0.7)1−xPrxY0.1O3−δ, 0 ≤ x ≤ 1. Structural phase transitions mapped as a function of temperature and composition by highresolution neutron powder diffraction and synchrotron X-ray diffraction reveal higher symmetry for lower Pr content and higher temperatures, with the largest stability field observed for rhombohedral symmetry (space group, R3̅c). Rietveld refinement, supported by magnetic-susceptibility measurements, indicates that partitioning of the B-site cations over the A and B perovskite sites compensates Ba substoichiometry in preference to A-site vacancy formation and that multiple cations are distributed over both sites. Electron−hole transport dominates electrical conductivity in both wet and dry oxidizing conditions, with total conductivity reaching a value of ∼0.5 S cm−1 for the x = 1 end-member in dry air at 1173 K. Higher electrical conductivity and the displacement of oxygen loss to higher temperatures with increasing Pr content both reflect the role of Pr in promoting hole formation at the expense of oxygen vacancies. In more reducing conditions (N2) and at low Pr contents, conductivity is higher in humidified atmospheres (∼0.023 atm pH2O) indicating a protonic contribution to transport, whereas the greater electron−hole conductivity with increasing Pr content results in lower conductivity in humidified N2 due to the creation of protonic defects and the consumption of holes.
PB American Chemical Society
SN 0020-1669
YR 2018
FD 2018
LK https://hdl.handle.net/20.500.14352/100187
UL https://hdl.handle.net/20.500.14352/100187
LA eng
NO Heras-Juaristi, G., Amador, U., Romero de Paz, J., Fuentes, R. O., Chinelatto, A. L., Ritter, C., ... & Mather, G. C. (2018). Structures, Phase Fields, and Mixed Protonic–Electronic Conductivity of Ba-Deficient, Pr-Substituted BaZr0. 7Ce0. 2Y0. 1O3− δ. Inorganic Chemistry, 57(23), 15023-15033.
NO We thank the MINECO, Spain (ENE2015-66183-R and MAT2016-78362-C4-1-R), CSIC, Spain (i-link0743), and CAPES, Brazil (PVE, Proceso 88881.03418/2013-1). Access to the neutron facilities at the Institut Laue Langevin (Grenoble, France) and the National Synchrotron Light Laboratory (LNLS, Campinas, Brazil) under grant 5-24-55(D2B) and research proposal D10B-XRD1-16166, respectively, is gratefully acknowledged. We also thank the FCT, PTDC/CTM-EME/6319/2014, QREN, FEDER, and COMPETE Portugal and the European Social Fund, European Union. U.A. acknowledges the Universidad San Pablo for financial support. We would also like to thank Steven Kermorvant and Alexandre Bosser of the IUT, University of Rennes (France), for assistance.
NO Ministerio de Economía y Competitividad (España)
NO Ministry of Education (Brazil) 
NO Consejo Superior de Investigaciones Científicas
DS Docta Complutense
RD 7 abr 2025