Electron traps on oxide surfaces: (H+)(e-) pairs stabilized on the surface of 17O enriched CaO.
(H+)(e-) pairs generated at the surface of polycrystalline CaO are analyzed for the first time in terms of the interaction of the unpaired electron spin with the nuclear spin of the 17O anions of the surface. CaO crystals enriched in the 17O isotope are prepared and the corresponding hyperfine coupling constants are measured in electron paramagentic resonance (EPR) spectra. The results are analyzed on the basis of cluster model density functional theory calculations. The computed hyperfine coupling constants for (H+)(e-) pairs formed on the edge, corner, and reverse corner sites of the CaO surface allow a tentative assignment of two observed spectral features to specific morphological surface sites.
Chiesa
Mario
M
Dipartimento di Chimica IFM, Università di Torino and NIS, Nanostructured Interfaces and Surfaces Center of Excellence, Via P. Giuria 7, 10125 Torino, Italy. m.chiesa@unito.it
Paganini
Maria Cristina
MC
Giamello
Elio
E
Di Valentin
Cristiana
C
Pacchioni
Gianfranco
G