Effect of Doping on Surface Reactivity and Conduction Mechanism in Sm-doped CeO2 Thin Films
- Univ. of Rome Tor Vergata (Italy)
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Science and Technology Facilities Council (STFC), Harwell Campus, Oxford (United Kingdom). Diamond Light Source, Ltd.
- ORNL
- University of Roma Tor Vergata, Italy
A systematic study by reversible and hysteretic electrochemical strain microscopy (ESM) in samples of Cerium oxide with different Sm content and in several working conditions allows disclosing the microscopic mechanism underlying the difference in electrical conduction mechanism and related surface activity, such as water adsorption and dissociation with subsequent proton liberation. We measure the behavior of the reversible hysteresis loops by changing temperature and humidity, both in standard ESM configuration and using the first order reversal curve method. The measurements have been performed at much lower temperature ranges with respect to alternative measuring techniques. Complementing our study with hard x-ray photoemission spectroscopy and irreversible scanning probe measurements we find that water incorporation is favored until the doping with Sm is too high to allow the presence of Ce3+. The influence of doping on the surface reactivity clearly emerges from all of our experimental results. We find that at lower Sm concentration proton conduction is prevalent, featured by lower activation energy and higher electrical conductivity. The defect concentrations determine the type of the prevalent charge carrier in a doping dependent manner.
- Research Organization:
- Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Sciences (CNMS)
- Sponsoring Organization:
- USDOE Office of Science (SC)
- Grant/Contract Number:
- AC05-00OR22725; CNMS2014-046
- OSTI ID:
- 1185545
- Alternate ID(s):
- OSTI ID: 1286788
- Journal Information:
- Advanced Functional Materials, Vol. 8, Issue 12
- Country of Publication:
- United States
- Language:
- English
Web of Science
Similar Records
The ionic conductivity of Sm‐doped ceria
Mechanisms underpinning the ultrahigh piezoelectricity in Sm-doped 0.705Pb(Mg1/3Nb2/3)O3-0.295PbTiO3: Temperature-induced metastable local structure and field-induced polarization rotation