In situ X-ray studies

Other studies on heteropoly anions include electron paramagnetic resonance on the reduced forms of heteropoly compounds196, 198 and thermal and in situ X-ray studies of some heteropoly compounds200. No thermodynamic data are available on heteropoly compounds. 

Although the bulk of detailed work has been undertaken on v-SiOj, in situ x-ray studies of molten silicates at high temperature have confirmed that Si is coordinated to four oxygens in the molten as well as the glassy state (Waseda and Toguri, 1977, 1978) and yielded information on Si-0 bond lengths and some angular information (see Table 8.1). 

Iherzolite transition in the system Ca0-Mg0-Al203-Si02 revisited an in situ X-ray study. Geoehim. Cosmochim. Acta 66, 2109-2121. 

Dubrovinsky L. S., Saxena S. K., Tutti F., and Rekhi S. (2000) In situ X-ray study of thermal expansion and phase transition of iron at multimegabar pressure. Phys. Rev. Lett. 84, 1720-1723. 

The results from the in situ X-ray study of propylene-based ethylene-propylene copolymer during tensile deformation (36) are described as follows, because the deduced molecular mechanism appears to be universal in all elastomeric polyolefin copolymers. The stress-strain curves and selected WAXD patterns during extension up to strain 5.0 and subsequent retraction back to strain 1.7 (i.e., at zero stress) in the first deformation cycle are shown in Fig. 8.22. 

Mezger M, Reichert H, Schoeder S, Okasinski J, Schroeder H, Dosch H, Palms D, Ralston J, Honkimaeki V (2(X)6) High-resolirdon in situ X-ray study of they hydrophobic gap at the water-octadecyl-trichlorosUane interace. PNAS 103(49) 18401-18404... 

Yoon W, Kim N, Yang X, McBreen J, Grey C (2003) Li-6 MAS NMR and in situ X-ray studies of lithium nickel manganese oxides. J Power Sources 119 649-653... 

Thus, the stacking faults and intergrain boimdaries are the most typical extended defects in the samples studied. The in situ X-ray studies of these... 

M. Mezger, H. Reichert, S. Schoder, J. Okasinski, H. Schroder, H. Dosch, D. Palms, J. Ralston, V. Honkimaki, High-resolution in situ X-ray study of the hydrophobic gap at the water-octadecyl-trichlorosilane interface, Proc. Natl. Acad. Sci. U.S.A. 103 (2006) 18401-18404. 

Wu S, Lipkowski J, Tyiiszczak T and Hitchcock A P 1997 Eariy stages of copper eiectrocrystaiiization eiectrochemicai and in situ x-ray absorption fine structure studies of coadsorption of copper and chioride at the Au(111) eiectrode surface J.Phys. Chem. B 101 10 310-22... 

Li J and Abruna FI D 1997 Coadsorption of sulphate/bisulphate anions with Fig cations during Fig underpotential deposition on Au (111) An In situ x-ray diffraction study J. Phys. Chem. B 101 244-52... 

You H, Zurawski DJ, Nagy Z, Yonco RM. 1994. In-situ X-ray reflectiyity study of incipient oxidation of Pt(lll) surface in electrol)Te-solutions. J Chem Phys 100 4699-4702. 

Lucas CA, Markovic NM. 2006. In-situ X-ray diffraction studies of the electrode/solution interface. In AUdre RC, Kolb DM, Lipkowski J, Ross PN, editors. Advances in Electrochemical Science and Engineering. Volume 9. New York Wiley-VCH, pp. 1-45. 

Ocko BM, Wang J, Davenport A, Isaacs H. 1990. In situ X-ray reflectivity and diffi action studies of the Au(OOl) reconstruction in an electrochemical cell. Phys Rev Lett 65 1466-1469. 

Tidswell IM, Markovic NM, Lucas C, Ross PN. 1993. In-situ X-ray scattering study of the Au(lOO) reconstructuin in alkaline and acid solution. Phys Rev B 47 16542. 

Wang JX, Marinkovic NS, Zajonz H, Ocko BM, Adzic RR. 2001. In situ X-ray reflectivity and voltammetry study of Ru(OOOl) surface oxidation in electrol3de solutions. J Phys Chem B 105 2809-2814. 

The effects of tin/palladium ratio, temperatnre, pressnre, and recycling were studied and correlated with catalyst characterization. The catalysts were characterized by chemisorption titrations, in situ X-Ray Diffraction (XRD), and Electron Spectroscopy for Chemical Analysis (ESCA). Chemisorption studies with hydrogen sulfide show lack of adsorption at higher Sn/Pd ratios. Carbon monoxide chemisorption indicates an increase in adsorption with increasing palladium concentration. One form of palladium is transformed to a new phase at 140°C by measurement of in situ variable temperature XRD. ESCA studies of the catalysts show that the presence of tin concentration increases the surface palladium concentration. ESCA data also indicates that recycled catalysts show no palladium sulfide formation at the surface but palladium cyanide is present. 

A number of surface diffraction techniques can be employed in the structural study of electrochemical interfaces, depending on the details of the system under study. For bulk materials or thick films (such that the X-ray beam only samples that layer) conventional diffraction experiments can be performed and, in fact, a number of in situ X-ray diffraction studies of this type have been reported.126 129 In the case of thin films or monolayers, two different techniques can be employed and these are the reflection-diffraction technique introduced by Marra and Eisenberger,3 ), 32 and the technique based on surface truncation rods.131 In the first case, the incident X-ray beam impinges on the sample at an angle below... 

In this paper we present results from independent studies on the stage 2 to stage 1 transition area that show some unexpected features (anomalies). The results are obtained by electrochemical impedance spectroscopy (EIS), entropy measurements (AS(x)) and in situ x-ray diffractometry (XRD). The aim is to understand the mechanism of stage transition dealing with the observed anomalies. 

Fransson L. M. L, Vaughey J. T., Benedek R., Edstrom K., Thomas J. O., Thackeray M. M., Phase transitions in lithiated Cu2Sb anodes for lithium batteries an in situ X-ray diffraction study, Electrochem. Commun., (2001) 3 (7), 317-323. 

There have been many recent studies in support of this mechanistic approach. Stepwise reductive formation of Ag3+ and Ag4+ clusters has been followed using spectroscopic methods by Henglein [33], Reduction of copper (II) to colloidal Cu protected by cationic surfactants (NR4+) through the intermediate Cu+ prior to nucleation of the particles [36] as monitored by in situ x-ray absorption spectroscopy is another example. The seed-mediated synthesis also serves as evidence in support of this mechanism [38-41],... 

Brown Jr., G. E., G. A. Parks, and C. J. Chisholm-Brause (1989), "In-Situ X-Ray Absorption Spectroscopic Studies of Ions at Oxide-Water Interfaces", Chimia43, 248-256. 

M. M. Gunter, T. Ressler, R. E. lentoft, and B. Bems, Redox behavior of copper oxide catalysts in the steam reforming of methanol studied by in situ X-ray diffraction and absorption spectroscopy, J. Catal. 203, 133-149 (2001). 

Although a great many intercalation compounds of LDHs have been prepared and characterized, there have been few studies of the kinetics and mechanism of the intercalation process. In their chapter, O Hare and colleagues describe how detailed information about these aspects may be obtained by means of time-resolved in situ X-ray powder diffraction experiments. 

D. Sun, F. Gingl, Y. Nakamura, H. Enoki, M. Bououdina, E. AMba, In situ X-ray diffraction study of hydrogen-induced phase decomposition in LaMg and La Mg, J. Alloys Compd. 333 (2002) 103-108. 

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