| dc.creator |
Domínguez-Ariza, David |
|
| dc.creator |
Sousa Romero, Carmen |
|
| dc.creator |
Illas i Riera, Francesc |
|
| dc.creator |
Ricci, Davide |
|
| dc.creator |
Pacchioni, Gianfranco |
|
| dc.date |
2010-01-22T12:01:11Z |
|
| dc.date |
2010-01-22T12:01:11Z |
|
| dc.date |
2003 |
|
| dc.date.accessioned |
2024-12-16T10:20:44Z |
|
| dc.date.available |
2024-12-16T10:20:44Z |
|
| dc.identifier |
0163-1829 |
|
| dc.identifier |
http://hdl.handle.net/2445/10809 |
|
| dc.identifier |
510405 |
|
| dc.identifier.uri |
http://fima-docencia.ub.edu:8080/xmlui/handle/123456789/11486 |
|
| dc.description |
Aggregates of oxygen vacancies (F centers) represent a particular form of point defects in ionic crystals. In this study we have considered the combination of two oxygen vacancies, the M center, in the bulk and on the surface of MgO by means of cluster model calculations. Both neutral and charged forms of the defect M and M+ have been taken into account. The ground state of the M center is characterized by the presence of two doubly occupied impurity levels in the gap of the material; in M+ centers the highest level is singly occupied. For the ground-state properties we used a gradient corrected density functional theory approach. The dipole-allowed singlet-to-singlet and doublet-to-doublet electronic transitions have been determined by means of explicitly correlated multireference second-order perturbation theory calculations. These have been compared with optical transitions determined with the time-dependent density functional theory formalism. The results show that bulk M and M+ centers give rise to intense absorptions at about 4.4 and 4.0 eV, respectively. Another less intense transition at 1.3 eV has also been found for the M+ center. On the surface the transitions occur at 1.6 eV (M+) and 2 eV (M). The results are compared with recently reported electron energy loss spectroscopy spectra on MgO thin films. |
|
| dc.format |
9 p. |
|
| dc.format |
application/pdf |
|
| dc.language |
eng |
|
| dc.publisher |
The American Physical Society |
|
| dc.relation |
Reproducció digital del document publicat en format paper, proporcionada per PROLA i http://dx.doi.org/10.1103/PhysRevB.68.054101 |
|
| dc.relation |
Physical Review B, 2003, vol. 68, núm. 5, p. 054101-1-054101-9 |
|
| dc.relation |
http://dx.doi.org/10.1103/PhysRevB.68.054101 |
|
| dc.rights |
(c) The American Physical Society, 2003 |
|
| dc.rights |
info:eu-repo/semantics/openAccess |
|
| dc.source |
Articles publicats en revistes (Ciència dels Materials i Química Física) |
|
| dc.subject |
Defectes cristal·lins |
|
| dc.subject |
Química de superfícies |
|
| dc.subject |
Química computacional |
|
| dc.subject |
Teoria del funcional de densitat |
|
| dc.subject |
Crystals defects |
|
| dc.subject |
Surface chemistry |
|
| dc.subject |
Computational chemistry |
|
| dc.subject |
Density functional theory |
|
| dc.title |
Ground- and excited-state properties of M-center oxygen vacancy aggregates in the bulk and the surface of MgO |
|
| dc.type |
info:eu-repo/semantics/article |
|
| dc.type |
info:eu-repo/semantics/publishedVersion |
|