The Homogeneous Nucleation Mechanism of Cu2O on Cu(001)

Ab initioatomistic thermodynamics study of the early stages of Cu(100) oxidation

“…For example, using in situ ultrahigh vacuum transmission electron microscopy, Zhou and Yang found that the substrate temperature affects the morphology of the Cu 2 O islands that grow on the Cu(100) surface during oxidation, resulting in triangular, hut, rod, and pyramid shapes. 9 To explain the formation of these selfassembled nanostructures, which could be used as building blocks for nanodevices, different driving forces have been suggested including atomic diffusion, 10 interfacial strain, 11,12 and minimizing surface energy. [13][14][15] The early stages of Cu(100) oxidation have been investigated by experimental and computational studies.…”

Oxygen adsorption-induced nanostructures and island formation on Cu{100}: Bridging the gap between the formation of surface confined oxygen chemisorption layer and oxide formation

“…Cu͑100͒ is reactive towards O 2 dissociation, and adsorption of O 2 and oxide formation have been extensively investigated on it by a wide array of techniques: low-energy electron diffraction ͑LEED͒, 8 scanning tunneling microscopy ͑STM͒/LEED, 9-16 molecular beam surface scattering ͑MBSS͒/reflection highenergy electron diffraction ͑RHEED͒/Auger electron spectroscopy ͑AES͒/thermal desorption mass spectrometry ͑TDMS͒/LEED, 17,18 surface stress change by crystal curvature technique/density functional theory ͑DFT͒/LEED, 19 LEED multiple-scattering analysis, 20 time-resolved verylow-energy electron diffraction ͑VLEED͒, 21 spot profile analysis low-energy electron diffraction/helium diffraction ͑HED͒, 22 high-resolution electron energy-loss spectroscopy ͑HREELS͒/LEED/AES, 23 HREELS/x-ray photoelectron spectroscopy ͑XPS͒, [24][25][26] hyperthermal O 2 molecular beam ͑HOMB͒/XPS, 27,28 near edge x-ray absorption fine structure ͑NEXAFS͒, 29 normal-emission photoelectron diffraction/NEXAFS/LEED, 30 surface-extended x-ray absorption fine structure ͑SEXAFS͒, 31 angle-and temperaturedependent SEXAFS, 32 angle-dependent NEXAFS and SEXAFS/LEED/XPS/AES/TDMS, 33 surface x-ray diffraction, 34 in situ synchrotron x-ray scattering, 35 transmission electron microscopy ͑TEM͒, [36][37][38][39][40][41][42][43][44][45] analytical electron microscopy ͑AEM͒, 46,47 and ab initio calculations. [48][49][50][51][52]…”

“…8,59 This suggests that adsorption of O 2 on Cu͑100͒ is only kinetically limited to 0.5 ML coverage and, as the present investigation demonstrates, by increasing the oxygen impingement rate on the surface ͑i.e., oxygen partial pressure͒, new surface structures leading to subsurface oxide formation can be obtained. The onset and growth of oxide on Cu͑100͒ and vicinal surfaces consisting of Cu͑100͒ terraces have been studied extensively by in situ TEM ͑above 423 K͒, [36][37][38][39][40][41][42][43][44][45] and by utilizing combinations of HREELS/XPS, [24][25][26] hyperthermal O 2 molecular beam ͑HOMB͒/XPS, 27,28 NEXAFS, 29 and MBSS. 17 All previous STM investigations [9][10][11][12][13][14][15][16] on Cu͑100͒ have been limited to oxygen coverages below 0.5 ML except our recent XPS/STM study that focused on the formation of subsurface Cu 2 O and CuO in the temperature range of 300-423 K. 60 In this paper we investigate physicochemical phenomena leading to oxide island nucleation on Cu͑100͒ by means of variable temperature scanning tunneling microscopy ͑VT-STM͒ and quantitative XPS as a function of O 2 pressure ͑8.0ϫ 10 −7 and 3.7ϫ 10 −2 mbar͒ at 373 K. We revisit the extensively studied surface confined oxygen adlayer and demonstrate that the ͑2 ͱ 2 ϫ ͱ 2͒R45°-O reconstruction is inert in the low pressure regime.…”

Energetics and kinetics of thec(2×2) to (22×Lee1, McGaughey2 2011Phys. Rev. B19040View full textAdd to dashboardCite

“…The only relevant next event is therefore a diffusion to a C or D site, which is discussed in Section IV B. The magnitudes of these barriers are comparable to the activation energy of Cu 2 O formation on the Cu(100) surface (1.4±0.2 eV) 33 and to the activation energy for Ag on the Ag 1ML/Mo(100) surface (2.5 eV).…”