Formation of one-dimensional molybdenum oxide on Mo(112)

Abstract

Abstract.The atomic structure of a reconstructed Mo(112)-O(2x3) surface has been revisited using photoelectron spectroscopy with synchr otron radiation, scanning tunneling microscopy, infrared reflection absorption spectroscopy and density functional theory. In contrast to previous models, the results are rationalized in terms of the formation of onedimensional, Mo=O terminated molybdenum oxide involving corner-sharing distorted [MoO 6 ] octahedra on the (1x3) reconstructed Mo(112) surface.

Quantitative structure determination using grazing scattering of fast atoms: Oxygen-induced missing-row reconstruction of Mo(112)

“…A p(1×3) phase is present for 35 L followed by a continuous transition to the p(2×3) phase. The emerging [h+ 1 2 α] streaks (h integer numbers and α almost continuous) were attributed to a high amount of antiphase domain boundaries [48,49,56,81]. The dosage for achieving specific superstructures is about a factor of 2 higher than in Ref.…”

“…For the phase p(1×3), considered as precursor for the formation of a MoO 2 layer [55,56], the intensity distribution of scattered atoms is very broad pointing to a rough surface. For the phase p(2×3), considered as one-dimensional strings of oxide [49], a very large rainbow angle is observed for scattering in the [10] direction. This implies the presence of a single, broad, symmetrical channel in line with the model presented by Kaya et al [49].…”

“…For the phase p(2×3), considered as one-dimensional strings of oxide [49], a very large rainbow angle is observed for scattering in the [10] direction. This implies the presence of a single, broad, symmetrical channel in line with the model presented by Kaya et al [49]. Due to the large width of the unit cell d [10] = 13.4Å, no Bragg diffraction spots could be resolved with the present setup.…”

“…The applications of molybdenum and molybdenum oxide in heterogenous catalysis, microelectronics, or corrosion protection has led to considerable interest in the study of oxygen adsorption on molybdenum single-crystal surfaces, as a precursor for molybdenum oxide and other thin oxide films [48,49]. Oxygen exposure at elevated temperatures often results in substantial reordering of the atoms of transitionmetal substrates, especially for surfaces with ridge-and-trough structure.…”

“…For a low dose of oxygen, a c(2×4) superstructure was observed which converts with increasing dose over p(2×1), superposition c(4×2) + p(1×2), and p(1×2) to p(1×3) and p(2×3) at a high dose [37,42,[52][53][54]. The latter phases are accompanied by considerable surface reconstructions and are considered as precursor for the formation of a MoO 2 layer or represent one-dimensional strings of molybdenum oxide [49,55,56]. All structures were prepared at elevated substrate temperatures or by annealing the as-deposited low-temperature films (T 800 K) which partly exhibit further structural phases with less order [54].…”