Azimuthal width

Several attempts to induce orientation by mechanical treatment have been reviewed 6). Trans-polyacetylene is not easily drawn but the m-rich material can be drawn to a draw ratio of above 3, with an increase in density to about 70% of the close-packed value. More recently Lugli et al. 377) reported a version of Shirakawa polyacetylene which can be drawn to a draw ratio of up to 8. The initial polymer is a m-rich material produced on a Ti-based catalyst of undisclosed composition and having an initial density of 0.9 g cm-3. On stretching, the density rises to 1.1 g cm-3 and optical and ir measurements show very high levels of dichroism. The (110) X-ray diffraction peak showed an azimuthal width of 11°. The unoriented material yields at 50 MPa while the oriented film breaks at a stress of 150 MPa. The oriented material, when iodine-doped, was 10 times as conductive (2000 S cm-1) as the unstretched film. By drawing polyacetylene as polymerized from solution in silicone oil, Basescu et al.15,16) were able to induce very high levels of orientation and a room temperature conductivity, after doping with iodine, of up to 1.5 x 10s S cm-1. 

Figure 4.30. The radial (r) and azimuthal (tp) positions of two diffraction maxima M and M Ar and A ip respectively is the radial width and azimuthal width.

The azimuthal width of the standard reflexes of the stretched iPP - if present - remains mainly constant also during following crystallisation processes by cooling. Cooling to about... 

Fig, 26. Experimental dispersion curve of the Kr monolayer and measured line width broadening As of the Kr creation phonon peaks. The solid line in the dispersion plot is the clean Pt(lll) Rayleigh phonon dispersion curve and the dashed line the longitudinal phonon bulk band edge of the Pt(l 11) substrate, both in the r Mn azimuth which is coincident with the r Kk, azimuth. 

X cos 30° A is the inter-row distance of the commensurate Xe structure in the same direction. From the measured polar and azimuthal peak widths in Fig. 32 we can also estimate average domain sizes of the incommensurate layer. For the FK direction, i.e. parallel to the walls, we obtain 350 A and for the perpendicular TM direction 50 A. 

In Figs. 4S and 46 we summarize the results obtained by these authors for the Ni(l IS) and Ni(l 13) surface. Figure 45 shows the peak width (FWHM) of the specular He beam scattered from the Ni(115) surface along the (5, S, 2) azimuth as a function of the incident angle 0,. The oscillation characterizes the step density. The lineshapes of the specular He peak are shown in Fig. 46 in a log-log plot for Ni(113) along the (3, 3,2) direction with the temperature as parameter. The profiles suggest the expected power-law behavior and the variation of the power exponent 7 (i.e. the slope) with temperature is obvious. 

Generally it is found that PPT fibres are highly oriented and that those variants with the lowest values of orientation angle exhibit the highest tensile modulus. Indeed the average crystallite orientations derived from azimuthal peak widths at half maximum intensities of the 200 reflections in Kevlar 49 and Kevlar 29 are found to be nine and eleven degrees respectively. 

Fig. 41a and b. Long period L (a) and azimuthal half width A

isothermal crystallization of oriented polyethyleneterephthalate with the initial birefringence Ario = 19 10 . The parameter is the temperature of crystallization ... 

W21 beamline and diffractometer [33]. A large number, 366 of which 267 were non-equivalent, of in-plane reflections arising from the reconstruction were measured. All peaks were exactly centred at the expected positions to within 0.001° of azimuthal rotation, which showed that the surface reconstruction is perfectly commensurate with the underlying bulk lattice. Their width and Lorentzian shape indicated an exponential decay in correlations with the decay length of -500 A. Several reconstruction diffraction rods were also measured. The absence of symmetry of the rod intensity with respect to =0 showed that the reconstruction has the minimal hexagonal symmetry p3. 

Figure 11.16. Optimum biasing time for different bias voltage. The circles mark hetero-epitaxial films, while the triangles correspond to specimens without significant azimuthal alignment. The biasing times fopt of the HOD films with minimum FWHM for the azimuthal tilt angle are connected by straight lines. The vertical extension of the bright area defines the width of the BEN process time window [293].

In this way, separate meridional intensity profiles were generated for each dimer, corrected for polarization, and plotted in the range of 0comparison with calculated intensity distributions. Similarly, azimuthal intensity distributions passing through the equatorial reflections (measured as a function of azimuthal angle from the meridian) were used to determine the Hermans order parameters (8). 

Fig. 10. Long period L and azimuthal half width Ajp of the SAXS maximum as a function of time t0 during a crystallization of oriented PET (initial birefringence An0 = 0.19). Parameter is the crystallization temperature...

RAR curves were plotted using equation (16), assuming a 17.2 GHz emission frequency, a 1.8 meter wide antenna (Ground Probe, 2011), and a beam width factor of 0.89 (ideal reflector antenna), leading to an azimuthal and elevation beam width of 8.72 mrad. 

The experimental setup for observing polarized SHG about the azimuthal angle for these films is as follows The sample was at the waist of a focused (100 mm lens) beam (1064 nm) from a ( -switched Nd YAG laser. The pulse width was 150 ns and the repetition rate was 1 KHz. The fundamental beam was polarized inside the laser cavity and a halfwave plate was used to control the polarization of the beam incident on... 

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