Chromium spectra

In XPS, chemical information is comparatively slowly acquired in a stepwise fashion along with the depth, with alternate cycles of sputtering and analysis. Examples of profiles through oxide films on pure iron and on Fe-12Cr-lMo alloy are shown in Fig. 2.9, in which the respective contributions from the metallic and oxide components of the iron and chromium spectra have been quantified [2.10]. In these examples the oxide films were only -5 nm thick on iron and -3 nm thick on the alloy. 

Figure 17 contains three chromium spectra of type III, the low amplitude spectra characteristic of metals, and one of type I. Chromium, a body-centered cubic metal, produces extended fine structure. 

This characteristic of RAIR can be observed experimentally. Fig. 8 shows the transmission spectrum of polydimethylsiloxane (PDMS) while Fig. 9 shows the RAIR spectrum of a thin film of PDMS spin-coated onto a chromium substrate. It can be observed that the bands near 1024 and 1095 cm have similar intensities in the transmission spectra but the band at higher frequencies is clearly much more intense in the RAIR spectrum. This change in relative intensity when PDMS is deposited onto a reflecting substrate is related to optical effects and is not related to orientation effects. 

The C(ls) and 0(ls) spectra of polyphenylene ether (PPE) before and after evaporation of chromium onto the surface are shown in Fig. 23. C(ls) spectra of neat PPE consisted of two components, near 284.6 and 286.0 eV, that were assigned to carbon atoms in the benzene and methyl groups and in the ether groups, respectively. The 0(ls) spectrum consisted of a single peak, near 533.4 eV, that was assigned to the ether oxygen atoms. After evaporation of chromium, a new peak related to formation of Cr202 was observed near 531.0 eV. 

It is clear that an ah initio calculation of the ground state of AF Cr, based on actual experimental data on the magnetic structure, would be at the moment absolutely unfeasible. That is why most calculations are performed for a vector Q = 2ir/a (1,0,0). In this case Cr has a CsCl unit cell. The local magnetic moments at different atoms are equal in magnitude but opposite in direction. Such an approach is used, in particular, in papers [2, 3, 4], in which the electronic structure of Cr is calculated within the framework of spin density functional theory. Our paper [6] is devoted to the study of the influence of relativistic effects on the electronic structure of chromium. The results of calculations demonstrate that the relativistic effects completely change the structure of the Or electron spectrum, which leads to its anisotropy for the directions being identical in the non-relativistic approach. 

AF Cr at 118/f, manifests itself in the fact that the longitudinal polarization of the SDW changes to the transversal one. From the standpoint of electronic structure, the nature of such SF transition in chromium is still unclear. Moreover, this transition is unlikely to be explained within the framework of non relativistic treatment, the nonrelativistic electron spectrum being identical for the longitudinal and transversal SDW. 

The broad spectrum of the raw goods occurring in the leather and fur industry [95] necessitates various wet treatment processes in which surfactants and emulsifiers play a big role, e.g., in the regeneration of raw goods, which are preserved with salt, or by drying short-chain sulfosuccinates. To achieve hydro-phobizing effects, sulfosuccinate as emulsifiers are fixed on the surface by salts of aluminum or chromium. 

C02-0012. Figure 2-17 gives the isotopic composition of naturaiiy occurring chromium (Cr). Draw a bar graph that shows the mass spectrum of Cr. 

C02-0084. The pie chart in Figure 2-17 shows the isotopic abundances for chromium. Sketch the mass spectrum of this eiement. 

This spectrum was obtained from the surface of a sample of an iron-chromium-nickel alloy, and peaks from these elements, resulting from LMM transitions, are identified together with those from contaminants such as carbon, sulphur and oxygen. 

The electron paramagnetic resonance spectrum of transition metal ions has been widely used to interpret the state of these ions in systems of catalytic interest. Major emphasis has been placed on supported chromia because of its catalytic importance in low-pressure ethylene polymerization and other commercial reactions. Earlier work on chromia-alumina catalysts has been reviewed by Poole and Maclver 146). On alumina it appears that the chromium is present in three general forms the S phase, which is isolated Cr3+ on the surface or in the lattice the 0 phase, which is clusters of Cr3+ and the y phase, which is isolated Cr5+ on the surface. The S and 0... 

G.A. Ozin, University of Toronto In our Cr/CO matrix cocondensation experiments (Angew. Chem., Int. Ed. Eng. 1975, 14, 292), we reported evidence for the facile formation of a binuclear chromium carbonyl complex Cr2(CO)i0 or Cr2 (CCOi x which could be described as square pyramidal Cr(CO)5 weakly interacting with either a Cr(CO)5 or Cr(CO)6 moiety in the vacant (sixth) site. As a result, the infrared spectrum of this "weakly-coupled" binuclear species closely resembled that of the mononuclear fragment Cr(CO)5. I would like to ask you, whether or not you have any evidence for the existence of such a binuclear species in your Cr(CO)6 /Xe cryogenic solutions following various photolysis treatments. 

The Cr/Si02 catalyst is made by spin-coat impregnation of the flat silica support with a solution of chromic acid in water. Figure 9.25 shows the Cr XPS spectrum of the catalyst after drying. Chromium is present as a hydrated Cr(VI) oxide, with a Cr 2p binding energy characteristic of chromate species, as the reference spectra in the lower half of the figure show. An essential step in the... 

Figure 6. Tunneling spectrum of benzoic acid chromium tricarbonyl adsorbed on an Al-Oxide-Pb junction.

Figure 4 is a good example of satellite structure associated with a surface species. The chromium 2p /2,l/2 spectrum results from the reaction of the dichromate ion,, with galena to yield both... 

The steady-state free-procession (SSFP) technique was used with no NOE, and in the case of aniline the T of the 15N was reduced by addition of chromium acetylacetate as a relaxation reagent to the sample. The 15N spectrum of aniline showed a single broad line (Avi/2 = 42 Hz) in which, because of proton exchange125,126, there is no evidence of N H coupling (J = 80 Hz). 

---