Nucleation of Pd dimers at defect sites of the MgO(100) surface.
Point defects on oxide surfaces are presumed to be preferential nucleation sites for supported metal clusters. Under typical growth conditions, dimers constitute the first step in island nucleation. First-principles calculations on the formation of Pd dimers on regular and defect sites of the MgO(100) surface show that nucleation occurs with large dimer binding energies at divacancies and charged oxygen vacancies (F+ centers), while it is less favorable on steps and neutral F centers. The extensive database of defect trapping/attachment properties gives a firm basis to rationalize recent atomic-force microscopy findings and provides guidelines valid, in general, for ionic substrates.
Giordano
Livia
L
Dipartimento di Scienza dei Materiali, Università di Milano-Bicocca, Istituto Nazionale per la Fisica della Materia, Via R. Cozzi, 53, 20125, Milano, Italy.
Di Valentin
Cristiana
C
Goniakowski
Jacek
J
Pacchioni
Gianfranco
G