Spectroscopic studies films

X-ray photoelectron spectroscopic study of the spontaneously passive amorphous Fe-10Cr-13P-7C alloy in 1 N HCl revealed that the passive film consists of Cr, 0 , OH" and HjO, and hence the passive film has been called a passive hydrated chromium oxyhydroxide film (CrO (OH)j Subsequent investigations have revealed that... 

Duffy NW, Lane DW, Ozsan ME, Peter LM, Rogers KD, Wang RL (2000) Structural and spectroscopic studies of CdS/CdTe heterojunction cells fabricated by electrodeposition. Thin Sohd Films 361 314-320... 

Kishi, K and Ikeda, S. (1974) X-ray photoelectron spectroscopic study of the reaction of evaporated metal films with chlorine gas. The Journal of Physical Chemistry, 78, 107—112. 

Dickinson T, Povey AP, Sherwood PMA. 1975. X-ray photoelectron spectroscopic studies of oxide-films on platinum and gold electrodes. J Chem Soc Faraday Trans 171 298-311. 

IR and Raman spectroscopic studies on films and powders of PDHS indicate that the hexyl side chains are crystallizing into a hydrocarbon type matrix (40). This is indicated by the presence of a number of sharp characteristic alkane bands which become dramatically broadened above the transition temperature. Similar changes are observed for n-hexane below and above the melting point. CPMAS 29Si NMR studies on PDHS also show that the rotational freedom of the side chains increases markedly above the transition temperature (41,42). All of the spectral evidence... 

With increasing concentration of DHB, the photoproduct forms more slowly, as evidenced by decreasing loss of fluorescence intensity (Table I, entries 1-3). Nevertheless, the concentration of photoproduct(s) and RET from the polymer to photoproduct(s) are expected to increase with time, and stabilization of the polymer will eventually depend upon the capability of the photoproduct(s) to dissipate excitation energy imparted in the RET process. The observed decrease in stabilization efficiency by DHB (based on film discoloration) with exposure time in an accelerometer indicates that DHB is more effective than the photoproduct(s) in dissipating the light energy. Similar spectroscopic studies on polystyrene have led to the same conclusion in this case, as well.6... 

The physical and chemical properties of MgO films prepared by the sol-gel technique were the area interest of the examinations presented by Shukla75. The aim of mentioned work was to produce films with nano size particles so as to employ them for the sensor applications, as adsorption in such films increases many folds due to the increase of surface area. Infra-red spectroscopic studies indicated the presence of solvent in the precursor, which helped in decomposition to nano-particles during nucleation of the film. The MgO sol-gel films were deposited on the glass rod bend in U-shape for humidity sensor. 

L.M. Siperko and T. Kuwana, Electrochemical and spectroscopic studies of metal hexacyanometalate films. I. Cupric hexacyanoferrate. J. Electrochem. Soc. 130, 396-402 (1983). 

D. A. Higgins, M. M. Collinson, G. Saroja and A. M. Bardo, Single-Molecule Spectroscopic Studies of Nanoscale Heterogeneity in Organically Modified Silicate Thin Films, Chem. Mater., 2002, 14, 3734. 

Sonoyama, M., Miyazawa, M., Katagiri, G., and Ishida, H. (1997). Dynamic FT-IR spectroscopic studies of silk fibroin films. Appl. Spectrosc. 51, 545-547. 

Figure 21. Experimental arrangement for monitoring optical emission from an r.f plasma. The photomultiplier tube (PMT) and picoammeter detection electronics are frequently replaced with photodiode arrays and photographic film in many spectroscopic studies.

Whereas the surface interaction between [Mo(CO)6] and oxide supports were extensively studied and reactivity features generally well described, in depth characterization of the final deposif was offen neglecfed in the spectroscopic studies. On the other hand, many CVD studies carried out with zerova-lent carbonyl precursors revealed that incorporation of significant amounts of carbon and oxygen takes place. Additional studies are thus needed to correlate the influence of the state of the surface of the substrate to the chemical purity of the deposited ultra-thin films or nanoparticles. Probably, and as shown in other cases, the addition of a reactive gas in the system could also improve the quality of the films. 

The HREEL technique can be used in several ways for detailed spectroscopic studies of vibrational and electronic excitation within the atomic and molecular films... 

All the methods used to evaporate metals for atom synthesis were developed originally for the deposition of thin metal films. The more important of these techniques are shown schematically in Fig. la-d. Most of the evaporation devices can be scaled to give amounts of metal ranging from a few milligrams per hour for spectroscopic studies to 1-50 gm/hour for preparative synthetic purposes. Evaporation of metals from heated crucibles, boats, or wires (Fig. la-c) generally gives metal atoms in their ground electronic state. Electronic excitation of atoms is possible when metals are vaporized from arcs, by electron bombardment, or with a laser beam (Fig. Id). The lifetime of the excited states of... 

Infrared spectroscopic studies have been particularly useful in demonstrating the generality of this reaction. The spectra of the films of the complexes, obtained by depositing each of the metal vapors and excess 1,5-COD on a cold window and pumping off the excess ligand at -70°C, are all extremely similar, i.e., the spectra of the new compounds of Fe, Co, and Pd are almost identical to the spectrum of Ni(COD)2 with its known tetrahedral structure (25). 

In our spectroscopic study, where no potential was applied to the metal, albumin did not appear to exhibit a corrosive effect on the thin metal films. If metallic copper or nickel is ionized or solubilized and removed from the surface, the metallic layer will decrease in thickness. Metals absorb strongly in the mid-infrared and thus, a decrease in the thickness of this absorbing layer would result in an increase in the penetration depth of the evanescent... 

Figure 4.10 Reprinted from Tribol. Int., Vol. 25, P.A. Willermet, R.O. Carter, III and N.E. Boulos, Lubricant-derived tribochemical films-An infra-red spectroscopic study, pp. 371-380. Copyright 1992, with permission from Elsevier.

Distillation is a method in which a fulleride film with a nominal starting composition M C is heated for a prolonged period in ultrahigh vacuum. Depending on the starting composition and the stable phases of the system, either fullerene molecules or metal intercalant atoms evaporate from the film, driving the composition towards a stable phase [see Poirier DM, Weaver JH (1993) Phys Rev B 47 10959]. This method enables phase-pure films of intercalated fullerenes to be produced for spectroscopic studies. The low quantities in... 

W. M. Lau, Use of Surface Charging in X-Ray Photoelectron Spectroscopic Studies of Ultrathin Dielectric Films on Semiconductors, Appl. Phys. Lett. 54, 338-340 (1989). 

The experimental aspects of ex situ FUR spectroscopic studies of sensitive electrodes (e.g., Li and Ca surfaces) using a purged spectrometer (not in a glove box) have been described in detail in Refs. 36-38, 92, and 93. Briefly, it is possible to analyze thin surface films on active metal, using a reflectance mode, while the active surface is in contact with a KBr or NaCl polished window. In Refs. 37 and 38, a possible organization of the measurement chamber of an FTIR spectrometer for such measurements is described. It should be noted, however, that the performance of such measurements when the spectrometer is placed in the glove box is much more elegant and easier. 

We examined the representative esters, y-butyrolactone (BL), methyl formate (MF), and methyl acetate (MA). Figures 16 and 17 show FTIR spectra measured (ex situ) from noble metal electrodes polarized to low potentials in LiC104 solutions of BL and MF, respectively [30,39], As shown in these figures, at the onset reduction potential of around 1.3-1.2 V (Li/Li+), stable surface films precipitate on the electrode surfaces. Table 1 shows the spectral analysis for the surface films formed on noble metals at low potentials in BL. The conclusion drawn from the spectroscopic study is that the major surface compound formed is the dilithiated cyclic P-keto ester, which is similar to the electrolysis product of BL in TAA salt solutions (Scheme 2). 

The surface chemistry of Li in ethereal solutions has been studied rigorously by several groups. Koch et al. [72-74] studied the surface layers formed on Li in THF and 2Me-THF solutions of LiAsF6, which appear as brown films covering the electrodes. They concluded that these films are polymers of lithiated arsenic oxide that contain additional functional groups such as F, RCT, etc. However, these conclusions did not result from direct spectroscopic studies of Li surfaces. Important, indirect information on the composition of the surface films formed... 

Li reacts readily with 02 to form a Li20 film as the most stable product. However, Li202 and Li02 can also be formed at the outer part of such a film. The saturation concentration of 02 at room temperature in organic polar aprotic solutions is estimated in the order of 10 -10 4 M [218], Nevertheless, FTIR spectroscopic studies of pairs of Li electrodes treated identically in the same solutions, with the only difference being that one solution was saturated with oxygen, revealed that the presence of 02 (even in such low concentrations) influences the Li surface chemistry in alkyl carbonates and ethereal solutions [19,176],... 

Impedance spectroscopic studies of Li electrodes in polymeric electrolyte systems by many groups [388-402] have provided clear evidence that Li electrodes in polymeric electrolyte systems are covered by surface films. These grow during storage and control the electrochemical behavior of these systems. This is also true for the least reactive systems based on PEO [403],... 

Kim, K., C. Seo and H. Cheong (2006b). Photochromic mechanism in a-W03 thin films based on Raman spectroscopic studies. Journal of the Korean Physical Society, 48(6), 1657-1660. 

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