Photon-stimulated ion desorption from molybdenum oxides following Mo 2p_3/2 excitation

Photon-stimulated ion desorption from solid MoO3 following the Mo 2p_3/2 resonant transition has been investigated. In the XANES spectrum, Mo 2p_3/2 peak is split into two components corresponding to the excitations from Mo 2p_3/2 into the t_2g and eg orbitals. It was observed that the desorption yield of O+ ions at the Mo 2p_3/2 ⇒ e_g resonance is higher than that at the Mo 2p_3/2 ⇒ t_2g resonance. The Auger decay spectra reveal that there exist two kinds of spectator Auger decays. The high desorption yield at the 2p_3/2 ⇒ e_g resonance is interpreted by the fast breaking of the Mo-O bond due to the localization of the electrons in the highly antibonding e_g.