Annealing surfaces

Surface diffusion and electrochemically annealed surfaces, 86 Surface potential... 

Figure 4. XPS Ti(2p) core level after methylacetylene adsorption at 265 K on the 575 K-annealed surface.

Figure 8.10 LEIS spectra of Pt3Co (a) lightly sputtered surface with 0.5 keV Ar ions (b) annealed surface at lOOOK. (Reprinted with permission from Stamenkovic et al. [2002]. Copyright 2002. The American Chemical Society.)...

The further oxidation of this annealed [Ni0(100)+c(2x2)-0] layer is also reflected in the FTIR spectrum shown in Figure 3e. The NiO substrate in this spectrum was prepared by an additional exposure of 400 L O2 at 300 K to the annealed surface prior to the adsorption of CO. By comparing Figure 3d and Figure 3e, one can obtain important information concerning the further oxidation of the annealed NiO/Ni(100) surface. In agreement with our XPS data, the further oxidation occurs only on the c(2x2)-0 region, as indicated by the disappearance of the c(2x2)-0... 

Wiederhorn, S.M. and Lawn, B.R. (1979), Strength degradation of glass impacted with sharp particles I, Annealed surfaces , J. Am. Ceram. Soc., 62(1-2), 66-70. 

Fig. 7 X-ray photoelectron spectra of n-CuInSe2 of clean surfaces, Cl2 covered surfaces and annealed surfaces.

On defective surfaces, for example after Ar bombardment, surface states appear in the band gap region [203]. They were assigned to Ti -O-vacancy complexes [202]. Various reconstructions have been observed on vacuum annealed surfaces (2 x 2) [204], ( /5 x /5)R26.6° [205-208], c(2 x 2)[209]. They were assigned to an ordering of oxygen vacancies, the latter reconstruction being possibly due to Ca segregation on the surface. Simula-... 

In the vacuum chamber, air annealed surfaces were immediately p(2x2) reconstmcted and GIXS data were recorded after such an ex situ sample preparation because further treatments proved ineffective. Annealing in UHV leads to decomposition and formation of Ni clusters [100]. Annealing under up to 10 mbar O2 at 700K removes the residual C contamination but drastically transforms the internal structure of the reconstruction. 

A recent paper [125] describes a GIXS study that allowed determination of the surface termination. Chemically treated surfaces were found to be terminated by a Ti02 plane, and annealed surfaces were mostly terminated with a Ti02 plane, with a small portion covered by a SrO plane. 

An example for a typical terrace-step structure is shown in Fig. 8. Step edges on annealed surfaces run predominantly parallel to <001> and ... 

Instead of the usual sputter/annealing preparation of new crystals, oxygen plasma treatment appears to be a quite efficient treatment for producing clean, (1x1) terminated terraces [83]. Plasma treatment removed Ca (that often segregates to the surface initially) quickly. At relatively low temperature it produced larger terraces (1500 A in width) and straight step edges than typically found on sputtered/annealed surfaces. 

Sn rows are exposed (Fig. 9e). The 102 facets may be preferred with respect to lOn with even n > 2, because 102 affords the steepest slope with the smallest steps. On 104 three row wide Pt steps occur which are less stable than terraces mixed with Sn (Fig. 9d). Note that due to the lack of chemical order within the pyramids the facets are not forced to even step height unlike the (100) and (110) surfaces of the well-annealed surface. Still, there remain open questions, for instance the balance between pyramid formation and the three row reconstruction of the flat parts of (001), both structures being part of the effort to relieve the stress due to the Sn deficiency. 

Fig. 3 STM images of Ag(lll) with different coverages of deposited Sb. The left-hand image corresponds to an area of 60 x 60 with a coverage of 0.12 ML at room temperature. The right-hand image is of an area of 300 x 200 of an annealed surface with a coverage of...

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