The oxidation of zinc in air studied by XPS and AES

Abstract

The oxidation of zinc in air at 294 K has been studied for exposure times from 1 min to 150 h. The fraction of zinc in the Zn+2 valence state has been determined by high resolution Auger electron spectroscopy. Surface oxide thickness was measured by using AES with argon ion sputter etching. The adsorbed oxygen was shown by x-ray photoelectron spectroscopy to be in two states, one corresponding to O−2 in ZnO, the other being chemisorbed oxygen. The two O1s photoelectron peaks were partially resolved by means of a van Cittert-type deconvolution calculation and the relative separation was found to be 1.7 eV, in agreement with that for low level O2 adsorption of polycrystalline zinc under UHV conditions.1 The effect of temperature was also determined in the range of 294–573 K. The fraction of zinc in the Zn+2 valence state after 1 h exposure was found to increase nearly linearly with temperature, with ZnO formation complete at 573 K.

Controlled adsorption of titanium(IV) oxide particles on electroplated zinc coatings to improve the corrosion resistance of chromium(VI)‐free conversion layers

“…The determined isoelectric point (IEP) of the titania suspension with a solid content of 13.5 wt.% amounts to IEP TiO2 = 6.7, which is in reasonable agreement with the values reported in other studies [21][22][23].…”

“…The isoelectric point is a very important parameter to characterize the properties of the particle surfaces in an aqueous suspension and their agglomeration and adsorption behavior during the dip-coating process. The isoelectric point is defined as the pH value, where the zeta potential is zero [21]. That means the particle charging is zero and hence only destabilizing forces (van der Waals, gravity) act on the particles.…”

Identifying surface structural changes in a newly-developed Ga-based alloy with melting temperature below 10 °C

“…For Zn, the peaks located at 1021.8 eV and 1044.8 eV correspond to Zn 2p 3/2 and Zn 2p 1/2 states, respectively. Since Zn 2p 3/2 peak showed a small shift of about 0.4 eV between the metallic (Zn 0 ) and oxidation (Zn 2+ ) states, it is really hard to distinguish them from present Zn 2p spectra [44,45] . But according to the thermodynamic points, ZnGa 2 O 4 has the standard molar enthalpy of formation at 298 K of -1473 kJmol -1 [46] , which is considerably more stable than gallium oxide (-1089.1 kJmol -1 ) and zinc oxide (-350.5 kJmol -1 ) [47] , suggesting that ZnGa 2 O 4 might be preferentially formed on the surface of liquid GISZ alloy.…”

“…As for O 1s spectrum in Fig. S2, it displays double peaks, where the low binding energy peak situated at about 530.5 eV can be ascribed to Ga-O and Zn-O bonds, the high binding energy peak around 532 eV is usually attributed to chemisorbed or dissociated oxygen or OH species on the surface [44,45] .…”

Resistivity Stability of Ga Doped ZnO Thin Films with Heat Treatment in Air and Oxygen Atmospheres

“…The broadening of oxygen spectrum (Figure 3) is believed to be composed of two components located around 531 eV and 532 eV respectively. The low BE component is ascribed to covalently bonded oxygen in ZnO structure (lattice oxygen) while the high BE is attributed to the adsorbed oxygen [21][22][23]. The higher binding energy at 532 eV is usually attributed to chemisorbed or dissociated oxygen or OH species on the surface of the ZnO thin film, such as adsorbed H 2 O or adsorbed O 2 [24].…”