Tilt angle temperature dependence

Specific heat measurements show mainly a mean-field behavior with a sixth order term included in the free energy expression [53-57] (Fig. 7) however, the agreement between the model and the measurements of Cp in the neighborhood of the transition has been a controversial question in the milli-Kelvin temperature range, and especially in the smectic A phase [58]. For the tilt angle temperature dependence, mean-field [52, 59] and helium-like behavior [58] are reported. Helium-like behavior has been reported in one compound (Fig. 8), and the... 

The important issue of size effects was addressed by Karaborni and Siepmann [368]. They used the same chain model and other details employed in the Karaborni et al. simulations described earlier [362-365] and the 20-carbon chain. System sizes of 16, 64, and 256 molecules were employed with areas of 0.23, 0.25 and 0.27 nm molecule simulations with 64 molecules were also performed for areas ranging from 0.185 to 0.40 nm molecule . The temperature used was 275 K, as opposed to 300 K used in the previously discussed work by Karaborni et al. with the 20-carbon chain. At the smaller areas no significant system size dependence was found. However, the simulation at 0.27 nm molecule showed substantial differences between N = 64 and N = 256 in ordering and tilt angle. The 64-molecule system showed more order than the 256-molecule system and a slightly lower tilt angle. The pressure-area isotherm data for these simulations are not... 

Temperature dependence proton relaxivity 188 relaxation rate 144-5 Temperature-sensitive contrast agents 218-19 Th -" 368 Ti "" 347 Tilt angle 242 Time constant 14 Time correlation functions 76 Time-dependent mechanism 14 Time-dependent perturbation methods 23 Time-dependent perturbation theory 45-8 Titanium(III) 115,134-5,161 TPEN 224 TPPS 219... 

In Figure 5.10, the tilt angles tiqo were measured as a function of the CH4 concentration c and the substrate temperature T. It is seen that when c is low, the diamond film is (llO)-textured, while it is more (lOO)-textured as c is increased. The (100) texture is achieved at lower c when = 800 °C than when Ts > 800 °C. Thus, this figure clearly shows that a is dependent on both c and Tg. 

In any case, this concept of the distribution of the tilt angle in irradiated PMMA accounts satisfactorily for the experimental spectrum. It must be noted, however, that the spectrum observed for irradiated acrylic acid has been interpretated by Bamford etal. [91] assuming a mixture of two conformations Qx = 02 = 60° and 0 = 60°—a, 02 = 60°+ a, the mixing ratio of which depends on temperature. 

Figure 6.41. The dependence of the tilt angle 20 on temperature for (a) the small molecular mass ferroelectric liquid crystals LI, L2 and L3 and (b) their polymer counterparts PI, P2 and P3. (From Sekiya et al., 1993. Reproduced by permission of Taylor Francis, )...

Fig. 16. (Top) Temperature dependence of the magnetociystalline anisotropy constants Kt and K2 - K3 determined from torque experiments. (Bottom) Temperature dependence of the tilt angle. (After Yamada...

In the smectic C phase the rod-like molecules are arranged in diffuse layers where the molecules are tilted at a temperature-dependent angle with respect to the layer planes [8]. Thus the phase has C2h symmetry When the smectic C phase is formed from the smectic A phase upon cooling, the temperature dependence of the tilt angle approximately takes the form... 

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