Using all electron fully relativistic DFT calculations we, have computed the EPR properties of Au atoms bound to various sites of the MgO surface. Changes in g-tensor and hyperfine coupling constants provide a way to identify the gold adsorption site and to map the surface morphology by comparison of measured and calculated EPR spectra. We found a strong reduction of the isotropic hyperfine coupling constant, a(iso)(Au), for adsorbed gold compared to the free atom; this reduction, which is about 45\% for terrace sites, is more pronounced when Au interacts with low-coordinated sites like steps, edges and corners where it is about 60\%. The reduction of a(iso)(Au) is accompanied by a corresponding increase of the superhyperfine interaction with the surface oxygen sites, as measured by a(iso)(O-17). Large anisotropies in the g-tensor are computed for all sites.
DI VALENTIN, C., Scagnelli, A., Pacchioni, G., Risse, T., Freund, H. (2006). EPR properties of Au atoms adsorbed on various sites of the MgO(1 0 0) surface from relativistic DFT calculations. SURFACE SCIENCE, 600(12), 2434-2442 [10.1016/j.susc.2006.03.048].
EPR properties of Au atoms adsorbed on various sites of the MgO(1 0 0) surface from relativistic DFT calculations
DI VALENTIN, CRISTIANA;PACCHIONI, GIANFRANCO;
2006
Abstract
Using all electron fully relativistic DFT calculations we, have computed the EPR properties of Au atoms bound to various sites of the MgO surface. Changes in g-tensor and hyperfine coupling constants provide a way to identify the gold adsorption site and to map the surface morphology by comparison of measured and calculated EPR spectra. We found a strong reduction of the isotropic hyperfine coupling constant, a(iso)(Au), for adsorbed gold compared to the free atom; this reduction, which is about 45\% for terrace sites, is more pronounced when Au interacts with low-coordinated sites like steps, edges and corners where it is about 60\%. The reduction of a(iso)(Au) is accompanied by a corresponding increase of the superhyperfine interaction with the surface oxygen sites, as measured by a(iso)(O-17). Large anisotropies in the g-tensor are computed for all sites.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.