X-ray diffraction conductivity

X-ray diffraction conducted on the codeposited powder revealed that the deposit obtained from a suspension of gamma alumina, which had been partially converted to the alpha phase, contained both phases of alumina. Whereas, the powder codeposited from a suspension having a 50 50 mixture of alpha to gamma alumina powder, consisted only of the alpha phase. Using a parallel plate electrode configuration, Chen et al. [31] concluded that only alpha alumina can be codeposited. Chen also observed a difference in codeposition with copper when using two different phases of the titanium oxide particle system rutile readily codeposited but anatase titania did not... 

LB film prepared from stearic acid and containing TBTTF-Zn(dmit)2 charge transfer complex (and oxidized by iodine exposure) Absorption, FTIR spectroscopy, lowangle X-ray diffraction, conductivity measurements Maximum conductivities perpendicular and parallel to the LB film were determined to be 10-3Scm-t and4.3xl0 l Scm-1 122... 

This is the reason for numerous studies that have been conducted with X-ray diffraction, a method not described here. Suffice it to say that X-ray diffraction is useful in providing values of aromaticity, the distances between layers and between aliphatic chains, the thickness of particles, etc. 

Seehra, M. S., and Pavlovic, A. S., X-ray diffraction, thermal expansion, electrical conductivity, and optical microscopy studies of coal-derived graphites. Carbon, 1993, 31, 557 564. 

Infrared, X-ray diffraction, DTA, TG, electrical conductivity and solubility measurements have been used to investigate the mechanisms of tribochemical reactions between solids [385,386],... 

It is appropriate to emphasize again that mechanisms formulated on the basis of kinetic observations should, whenever possible, be supported by independent evidence, including, for example, (where appropriate) X-ray diffraction data (to recognize phases present and any topotactic relationships [1257]), reactivity studies of any possible (or postulated) intermediates, conductivity measurements (to determine the nature and mobilities of surface species and defects which may participate in reaction), influence on reaction rate of gaseous additives including products which may be adsorbed on active surfaces, microscopic examination (directions of interface advance, particle cracking, etc.), surface area determinations and any other relevant measurements. 

Graphite bisulfates are formed by heating graphite with a mixture of sulfuric and nitric acids. In the reaction, the graphite planes are partially oxidized. There is approximately one positive charge for every 24 carbon atoms, and the HS04 anions are distributed between the planes, (a) What effect is this oxidation likely to have on the electrical conductivity (b) What effect would you expect it to have on the x-ray diffraction pattern observed for this material Refer to Major Technique 3 on x-ray diffraction, which follows this set of exercises. 

Besides synthesis, current basic research on conducting polymers is concentrated on structural analysis. Structural parameters — e.g. regularity and homogeneity of chain structures, but also chain length — play an important role in our understanding of the properties of such materials. Research on electropolymerized polymers has concentrated on polypyrrole and polythiophene in particular and, more recently, on polyaniline as well, while of the chemically produced materials polyacetylene stih attracts greatest interest. Spectroscopic methods have proved particularly suitable for characterizing structural properties These comprise surface techniques such as XPS, AES or ATR, on the one hand, and the usual methods of structural analysis, such as NMR, ESR and X-ray diffraction techniques, on the other hand. 

Electron microscopy and X-ray diffraction experiments conducted on resilin-containing insect cuticle provided further support for resilin existing in the rubbery state as a crosslinked random network of protein chains. No fine structure was revealed by the electron microscopy experiments and zero crystallinity could be detected from the X-ray diffraction experiments. Furthermore, the diffraction... 

X-ray diffraction XRD was performed to determine the bulk crystalline phases of catalyst. It was conducted using a SIEMENS D-5000 X-ray diffractometer with CuX (k = 1.54439 A). The spectra were scanned at a rate of 2.4 degree/min in the range 20 = 20-80 degrees. 

A non-electrochemical technique which has been employed to alter the physical characteristics of a number of polymers is that of stress orientation [26, 27], in which the material is stressed whilst being converted to the desired form. This has the effect of aligning the polymer chains and increasing the degree of order in the material, and is obviously most applicable to materials which can be produced via a precursor polymer. With Durham polyacetylene (Section 4.2.1) increases in length in excess of a factor of twenty have been achieved, with concomitant increases in order, as shown by X-ray diffraction and by measurements of the anisotropy of the electrical conductivity perpendicular and parallel to the stretch direction. 

Figure 62 The unreacted (100), partially reacted (101), and completely reacted (102) diacetylene group-containing oligomers in the product from the reaction between 95 and Cp2Mo2(CO)6 (top). The X-ray diffraction spectrum (middle, left), TEM micrographs (middle, right), and conductivity plots (bottom) of the product from the reaction between 95 and Cp2Mo2(CO)6 after pyrolysis to 1000°C. (Adapted from ref. 130.)...

The experimental tools for this research were chronopotetiometry (galvanostatic cycling),25 atomic force microscopy (AFM),26,27 scanning electron microscopy (SEM), and X-ray diffraction (XRD).21,25 It should be mentioned that the AFM imaging was conducted in-situ under potential control and in a special homemade glove box filled with highly pure argon atmosphere. This system has been already described in detail in the literature.28... 

In-situ x-ray diffraction (XRD) was performed on a coin type cell with a 4x6 mm Kapton window coated with conductive thin copper layer. The graphite electrode was pressed against the Kapton window so as to be reached by the x-ray beam. After several lithiation/delithiation cycles under a C/10 rate between 1.5 and 0V, the cell was fully delithiated up to 1.5V. The cycle capacity achieved with the graphite electrode is about 360mAh/g. The cell was then re-lithiated under a slower rate of C/20. XRD patterns were taken for about five minutes every hour while the cell is under continuous discharge. As result the lithium composition x in LixC6 was incremented by 0.05 between two successive XRD scans. 

In 1983, Buelens et al. conducted studies using Linde-manufactured 0.05 pm gamma alumina powder [30]. This work using a RDE resulted in incorporation levels of 0.035 and 0.0175 wt%, i.e. no significant incorporation. Work published in 1987 by the same group resulted in codeposition of 1.45, 0.55 and 0.30 wt% [37]. Comparison of this latter work to the work from 1983 shows codeposition increased by more than an order of magnitude. While the absolute amounts may be questionable in accuracy, the relative increase is significant. Neither of the RDE studies [30, 37] involved x-ray diffraction verification of the Linde powders, presumably since Chen et al. [31] had published such verification. 

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