Amorphous scattering intensity

Distribution of amorphous scattering intensity, in particular, angular 20 position, depends on the sizes of cyclic fragment and side substituting agent (Figure 14). 

Percent Crystallinity. For samples that consist of a mixture of crystalline and amorphous material, it is possible to determine the percent of crystallinity by measuring the integrated intensity of sharp Bragg reflections and the integrated intensity of the very broad regions due to the amorphous scattering. 

Amorphous orientation average Crystalline orientation average Nuclear spin number Scattered intensity Scattered intensity Transmitted intensity... 

Fig. 7 Relative integrated intensities under the peaks (left scale) and relative degree of crystallinity (right scale) obtained from wide-angle X-ray scattering data for D7732C2310 quenched from T = 115 to 30°C. The cooling rate was 30°Cmin 1. The arrow indicates the nominal point at which the final temperature was reached. For convenience, the amorphous peak intensity has been divided by 5. (Reprinted with permission from [ 107]. Copyright 2003 American Chemical Society)...

The relative degree of crystallinity can also be estimated from the WAXS pattern from the ratio of the integrated intensity of the crystal peak to that of the total amorphous and crystalline scattering (Balta-Calleja and Vonk 1989). For PE, the amorphous scattering below the (110) peak (Fig. 5.7) is relatively insensitive to the degree of crystallinity, so the integrated area of the (110) reflection compared to the broad amorphous halo is directly proportional to XPE. However, the absolute degree of crystallinity cannot be determined in this way (Ryan et al. 1995). 

In Raman scattering, the excitation light couples to changes in the polarizability and first order transitions are allowed in crystalline silicon. (See Lannin (1984) for a discussion of Raman scattering in amorphous silicon.) The scattering intensity, as a function of the phonon frequency, co, is approximately... 

In the two-phase model [6], the material is assumed to consist of randomly distributed micropores surrounded by a matrix, mainly consisting of amorphous carbon. From the scattered intensity, the scattering cross section r/ir/dn as a function of the scattering vector q can be obtained, if correlation effects between the scattering entities are neglected. Thus, for randomly distributed pores with uniform sizes the scattering cross section is related to the number Ap of micropores and the contrast between the pore phase and the carbon matrix [7] ... 

Thus we have a function F k) which is obtained from the experimental scattering intensity in the -space, which is related to pair distribution in the real space for an amorphous solid. They are therefore related through a Fourier transform which can be written as... 

For the first time we have shown that the crystalline order of films made of LMW and HMW P3HT changes as a function of film thickness. For film thicknesses above 20 nm the film structure consists of randomly oriented nanocrystallites of 25-40 nm size diluted in an amorphous matrix. Using the ratio between the total amount of scattering intensity under Bragg peaks and that... 

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