Data di Pubblicazione:
2017
Citazione:
Effects of Dopant Ionic Radius on Cerium Reduction in Epitaxial Cerium Oxide Thin Films / N. Yang, P. Orgiani, E. Di Bartolomeo, V. Foglietti, P. Torelli, A.V. Ievlev, G. Rossi, S. Licoccia, G. Balestrino, S.V. Kalininf, C. Aruta. - In: JOURNAL OF PHYSICAL CHEMISTRY. C. - ISSN 1932-7447. - 121:16(2017 Apr 10), pp. 8841-8849. [10.1021/acs.jpcc.7b00386]
Abstract:
The role of trivalent rare-earth dopants on the cerium oxidation state has been systematically studied by in-situ photoemission spectroscopy with synchrotron radiation for 10mol% rare earth
doped epitaxial ceria films. It was found that dopant rare-earths with smaller ionic radius foster the formation of Ce3+ by releasing the stress strength induced by the cation substitution.
Decreasing the dopant ionic radius from La3+ to Yb3+ the out-of-plane axis parameter of the crystal lattice decreases without introducing macroscopic defects. The high crystal quality of our
films allowed us to comparatively study both the ionic conductivity and surface reactivity ruling out the influence of structural defects. The measured increase in the activation energy of films
and their enhanced surface reactivity can be explained in terms of the dopant ionic radius effects on the Ce4+Ce3+ reduction as a result of lattice relaxation. Such findings open new perspectives
in designing ceria-based materials with tailored properties by choosing suitable cation substitution.
Tipologia IRIS:
01 - Articolo su periodico
Elenco autori:
N. Yang, P. Orgiani, E. Di Bartolomeo, V. Foglietti, P. Torelli, A.V. Ievlev, G. Rossi, S. Licoccia, G. Balestrino, S.V. Kalininf, C. Aruta
Link alla scheda completa:
Progetto: