In these AFM measurements, the sharpened silicon probes of nomina

In these AFM measurements, the sharpened silicon probes of nominal tip radius of curvature 20 to 30 nm were used for imaging. A silicon tip is scanned across the surface of a sample at a constant force of 16 N/m. The operating head scans the substrate selleck up to 90 μm in X-Y and up to 6 μm in Z. This scanner includes a piezoelectric tube scanner, a laser, and a quadrate optical detector. Set points were chosen close to the free oscillation amplitude to minimize forces exerted on the interfacial species. Effective resonance frequencies inside the fluid were approximately 300 kHz. The maximum spatial resolution (1 nm) and vertical resolution (0.1

A) allows the revealing of the surface structure at atomic level. The AFM image analysis was carried out using commercial WSxM 4.0 (Nanotec Electronica, Madrid, Spain) software procedures to determine surface roughness that is represented by root mean square (RMS) parameter and the values

of average and maximum grain height. Other experimental details have been described in [7, 8]. Results and discussion Figure 1 shows the XPS survey spectra of the Ag-covered L-CVD SnO2 www.selleckchem.com/JNK.html nanolayers after the technological procedure described in Section ‘Methods’. Figure 1 XPS survey spectra of Ag-covered L-CVD SnO 2 nanolayers and subsequent processes. With from decreasing binding energy, the following core levels are verified: O1s, Sn3d doublet, Ag3d doublet, C1s, and Sn4d. It was the base for determination of their surface chemistry (including stoichiometry and contaminations) based

on the atomic sensitivity factor (ASF) approach [9] using the recently described procedure [5, 6]. The Ag-covered L-CVD SnO2 nanolayers freshly deposited on atomically clean Si(100) substrate were treated as a reference sample in our studies. They exhibit good purity because (apart from a very weak C1s peak at signal-to-noise (S/N) ratio of approximately 2) only the O1s, Sn3d, Ag3d find more related core level XPS peaks were measured. The shoulders at the low binding energy (BE) of Ag and Sn core level doublets are satellite features owed to the use of the non-monochromatized X-ray radiation. For this freshly deposited Ag-covered L-CVD SnO2 nanolayers, the relative [O]/[Sn] concentration was equal to 1.30 ± 0.05. This means that these nanolayers are a mixture of SnO and SnO2 in about 2:1 ratio with dominance of SnO in the layer. Using the same analytical procedure, the relative [Ag]/[Sn] concentration was determined as equal to 0.50 ± 0.05. It corresponds to about 0.5 nm (1 ML) of Ag atoms deposited at the top, as estimated also by the QMB. More in general the results of quantitative elemental surface of the spectra of Figure 1 are reported in Table 1.

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