Substrate plane

Figure 9-6. Crystal structure of hexa-phenyi, wliereby the solid gray bar represents the substrate plane. The motio-clinic unit cell is sketched in thin solid lines.

The two examples of adsorbed side chain substituted macromolecules, i.e., the poly(n-butyl acrylate) brush and the tris(p-undecyloxybenzyloxo) benzoate jacketed polystyrene, demonstrate two rather complementary aspects of the interaction of such molecules with a planar surface. In the first case the two-dimension to three-dimension transition results in a cooperative collapse of an extended coil conformation to a globule. The second case shows a rather high degree ordering with a distinct orientation of the backbone in the substrate plane. Combination of both effects and partial desorption can lead to a repta-tion-hke directed motion as depicted schematically in Fig. 36. 

Fig. 7 2D thickness-surface energy gradient library for mapping the effects of these parameters on the self-assembly of PS-b-PMMA block copolymer thin films. See text for a fuU description. Lq is the equilibrium self-assembly period and h is the film thickness. Dashed white lines delineate the neutral surface energy region, which exhibits nanostructures oriented perpendicular to the substrate plane. (Derived from [18] with permission)... 

Figure 6.39(a) shows the vs. T curve, normalized to the RT value, for a 100 nm thick a-/ -NPNN/glass film obtained from electron paramagnetic resonance (EPR) measurements with the static magnetic field applied perpendicular to the substrate plane. As previously shown in Fig. 3.19, the molecular a -planes are parallel to the substrate s surface. The data points closely follow the Curie-Weiss law = (T — w)/C, where C stands for the Curie constant. In this case w — —0.3 K, indicating that the net intermolecular interactions are weakly anfiferromagnetic. No hint of a transition at low temperature is observed. These results coincide with those derived from SQUID measurements on a single a-p-NPNN crystal (Tamura etal, 2003), where 0.5 < w < 0, which are displayed in Fig. 6.40. 

The dependence of the g-factor on temperature for both stabilized (a) and transformed (j6) phases with the static magnetic field applied perpendicularly to the substrate plane is shown in Fig. 6.41. At low temperature the g-factor decreases for... 

The hydrocarbon chains tilted at an angle of about 10° with respect to the normal to the substrate plane. 

Compared to bulk polymer mixtures, the interfacial behaviour of polymer blends is essentially different [341]. The demixing process in thin films is strongly affected by the thin film confinement and the interfacial interactions of the blend components with the confining phases (e.g., substrate and air). Even in the one-phase region of the phase diagram, preferential segregation of the components at one of the interfaces leads to a certain composition profile as a function of the distance from the free surfaces and the substrate plane [342,343]. In the... 

The best films on Pt/Ti/Si substrates are all polycrystalline, but tend to be strongly (111) orientated. At first sight, this may seem to be surprising, as the compositions are all tetragonal, with the polar axis along (001). However, it is found that if films are deposited with the cubic axes of the crystallites normal to the substrate plane, the tensile stresses in the film tend to... 

It is noted that the UV absorbance of the 10(g)-32(sc) sample decreased after the annealing treatment, as shown in Fig. 28a. Presumably, most polysilane chains lie down before annealing in the quartz substrate plane, as the film was prepared by the spin-coating technique. However, the thermal annealing treatment of semi-flexible 32 tends to orient some of the polymer chain segments perpendicularly and/or tilt them to the substrate plane, leading to the decrease in the apparent UV absorbance at 321 nm, as illustrated in Fig. 27. 

Unlike STM and AFM tips, which are sharp cones, a typical SECM tip is a conductive disk surrounded by the flat ring of insulating glass whose thickness is equivalent to several disk radii. Thus, a proper alignment of the tip with respect to the substrate surface is crucial (see also Section IV.B.2). Unless the tip surface is flat and strictly parallel to the substrate plane, the insulator touches the substrate first and prevents the conductive disk from coming close to its... 

Figure 3.23. Model of surface plane for the evaluation of the surface-molecule reorientation and its effects on the first substrate planes. The changes in the molecular orientations are replaced by a compression or dilation of a set of two planes connected elastically the missing forces are assumed to act only on the hatched planes. The parameters of the model are the distance d between two hatched planes and the distance a separating two nearest-neighbor hatched planes belonging to two different crystal planes. The interaction forces between planes of different "molecules" are indicated with the notation in the text [cf. (3.38)].

Figure 17.11 Calculated excitation enhancement at three different wavelengths for nanoaperture diameters ranging from 75nm to 250nm in both aluminum (left) and gold (right) films of ISOnm thickness. The intensity enhancement is averaged within lOnm thick volumes within the apertures, with VI representing the volume adjacent to the substrate. Plane wave excitation occurs from the substrate side. The upper region is...

Diffraction techniques (low-energy electron diffraction [34, 35], helium diffraction [36, 37] and grazing incidence X-ray diffraction [38]), scanning tunneling microscopy (STM) [36, 39, 40] and atomic force microscopy (AFM) [41] served to solidify the conclusions inferred from the less direct spectroscopic methods and provide additional structural details. The sulfur atoms order epitaxially on the substrate in a (x/3 X V3) R30° structure [36-38, 40, 41]. The angle of the sulfur-carbon bond with respect to the substrate plane is approximately 104° for alkanethiol monolayers [38, 42] and 180° for arylthiol SAMs [42, 43]. Given the agreement between the results obtained from direct structural methods and indirect spectroscopic methods, one... 

The X-ray diffraction pattern shown in Figure 4 indicates that nearly phase-pure Hg-1212 films can be obtained after the annealing step. The films are epitaxially aligned with the c axis normal to the substrate plane. The c-axis lattice parameter varies to some extent with the annealing treatment and has been obtained in the range of 12.48-12.6 A, which is somewhat smaller than the value observed in the bulk (12.71 A). 

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