Conductivity spectra scaling

Figure 12.20. Room-temperature conductivity (logarithmic scale) versus wavelength of the absorption in the 300-500 nm region of the UV-visible spectrum for various PPy films A = PPyFeEDTA (film 12) B = PPyCrEDTA (film 11) C = PPy(Cr(NCS)t ) (ref [22]) D = PPyCoCDTA(film 13) E = PPyCoEDTA (film 10) F = PPyCoPDTA (ref [22]) G == PPy Ci(oxX/ (ref [22]) and H = PPyPTS (film IB).

Figure 8.1 Sketch of QCM. The figure on the left is not to scale. The crystal thickness is around 300 jim. The sample, on the other hand, typically has a thickness of well below a micron. Right Conductance spectrum as obtained in impedance analysis. These measurements may be carried out on different harmonics. The ring-down technique (QCM-D] yields equivalent parameters," where the "dissipation" is given as D = 2T/f. Resonance frequency (/) and resonance bandwidth (F) are derived by fitting resonance curves to the experimental conductance spectra. The presence of the sample changes both / and F. in the modeling process one tries to reproduce the experimental values of A/ and AF.

Figure 19. The predicted low T heat conductivity. The no coupling case neglects phonon coupling effects on the ripplon spectrum. The (scaled) experimental data are taken from Smith [112] for a-Si02 (AsTj/ScOd 4.4) and from Freeman and Anderson [19] for polybutadiene (ksTg/Hcao — 2.5). The empirical universal lower T ratio l /l 150 [19], used explicitly here to superimpose our results on the experiment, was predicted by the present theory earlier within a factor of order unity, as explained in Section lllB. The effects of nonuniversaUty due to the phonon coupling are explained in Section IVF.

In addition to the above facilities which enable the analyst to save a considerable amount of time and to improve the quality of spectra, there is also the ability to store thousands of spectra on disk in a library of peak tables. Each table will consist of the wavenumbers of twenty or thirty of the most significant peaks in the spectrum together with the corresponding peak transmittance values. Several thousand tables can be stored on a single floppy disk and library searches can be conducted in a matter of seconds. After recording the spectrum of an unknown sample, a preliminary search to indicate possible structural features can be initiated. This may be followed by a complete search in which the peak table for the unknown is matched with as many library tables as the analyst has available. The computer then displays a list of ten to fifteen possible compounds in order of closeness of match using a graded scale, e.g. 0 to 9. 

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