Transition metal atoms incorporated into insulating materials (oxides in particular) can deeply modify their adsorption properties. In particular, charge transfer to adsorbed species can be induced by the presence of substitutional dopants, which introduce new electronic states in the band gap of the host crystal. Here we show, by means of density functional theory calculations, that Nb represents an excellent dopant to turn the rather inactive CaO(100) surface into an electron-rich support. The charge transfer ability of the doped material is shown by comparing the adsorption properties of the electronegative Au atoms on pure and Nb-doped CaO. While in the first case the CaO-Au bonding is relatively weak and the Au atom is essentially neutral, in the Nb-doped system a much stronger adhesion is found due to a net charge transfer from the Nb dopant and to the formation of a gold anion. This mechanism occurs also for Nb in high oxidation states. Nb is thus an excellent modifier of the calcium oxide properties. © 2014 IOP Publishing Ltd.

Prada, S., Giordano, L., Pacchioni, G. (2014). Nb-doped CaO: An efficient electron donor system. JOURNAL OF PHYSICS. CONDENSED MATTER, 26(31), 315004 [10.1088/0953-8984/26/31/315004].

Nb-doped CaO: An efficient electron donor system

PRADA, STEFANO
Primo
;
GIORDANO, LIVIA
Secondo
;
PACCHIONI, GIANFRANCO
Ultimo
2014

Abstract

Transition metal atoms incorporated into insulating materials (oxides in particular) can deeply modify their adsorption properties. In particular, charge transfer to adsorbed species can be induced by the presence of substitutional dopants, which introduce new electronic states in the band gap of the host crystal. Here we show, by means of density functional theory calculations, that Nb represents an excellent dopant to turn the rather inactive CaO(100) surface into an electron-rich support. The charge transfer ability of the doped material is shown by comparing the adsorption properties of the electronegative Au atoms on pure and Nb-doped CaO. While in the first case the CaO-Au bonding is relatively weak and the Au atom is essentially neutral, in the Nb-doped system a much stronger adhesion is found due to a net charge transfer from the Nb dopant and to the formation of a gold anion. This mechanism occurs also for Nb in high oxidation states. Nb is thus an excellent modifier of the calcium oxide properties. © 2014 IOP Publishing Ltd.
Articolo in rivista - Articolo scientifico
adsorption; charge transfer; doping; oxide; Condensed Matter Physics; Materials Science (all)
English
2014
26
31
315004
315004
none
Prada, S., Giordano, L., Pacchioni, G. (2014). Nb-doped CaO: An efficient electron donor system. JOURNAL OF PHYSICS. CONDENSED MATTER, 26(31), 315004 [10.1088/0953-8984/26/31/315004].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/64100
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