Crystal relaxation

In table 2 and 3 we present our results for the elastic constants and bulk moduli of the above metals and compare with experiment and first-principles calculations. The elastic constants are calculated by imposing an external strain on the crystal, relaxing any internal parameters (case of hep crystals) to obtain the energy as a function of the strain[8]. These calculations are also an output of onr TB approach, and especially for the hep materials, they would be very costly to be performed from first-principles. For the cubic materials the elastic constants are consistent with the LAPW values and are to within 1.5% of experiment. This is the accepted standard of comparison between first-principles calculations and experiment. An exception is Sr which has a very soft lattice and the accurate determination of elastic constants is problematic. For the hep materials our results are less accurate and specifically in Zr the is seriously underestimated. ... 

There are several reasons why the COZMgO(lOO) adsorption is particularly simple. First, the MgO(lOO) surface is imreconstructed and constitutes the unmodified (100) termination of the bulk MgO crystal. Relaxations of the... 

We consider the dynamics of the Freedericksz transition in the splay geometry upon the removal of the applied field [24-27]. Initially the liquid crystal director is aligned vertically by the applied field, as shown in Figure 5.17(a). When the applied field is removed, the liquid crystal relaxes back to the homogeneous state. The rotation of the molecules induces a macroscopic translational motion known as the backflow effect. The velocity of the flow is... 

For the liquid crystal in the homeotropic state, when the applied field is turned down, there are two relaxation modes. One is the H-F mode in which the liquid crystal relaxes into the fingerprint state (and then to the focal conic state) as discussed in the previous section. The other is the H-P mode in which the liquid crystal relaxes into the planar state [76,77]. The rotation of the liquid crystal in the H-P mode is shown in Figure 10.28. The liquid crystal forms a conic helical... 

In summary, if the hquid crystal is in the homeotropic state and the applied field is reduced, there are two possible relaxation modes. If the applied field is reduced to the region liquid crystal relaxes slowly into the fingerprint state and then to the focal conic state when the apphed field is reduced further. If the applied field is reduced below Ehpy the hquid crystal relaxes quickly into the transient planar state and then to the stable planar state. In bistable Ch reflective displays, the way to switch the liquid crystal from the focal conic state to the planar state is by first applying a high field to switch it to the homeotropic state, and then turning off the field quickly to allow it to relax to the planar state. 

Structural experiments required longer (3 min) exposure time (at 260 mA beam current). At room temperature the first exposure allowed the imaging of the monomer crystal. Subsequent irradiation (12 min) completed the process. Simultaneously, the crystal (1x1x0.1cm ) deformed to become concave to the beam reaching a maximum curvature of 1cm radius after 3 min. On continued irradiation the crystal relaxed back to planarity. 

LaFj -F NMR 100-560 single crystal relaxation times, T2, Ti Goldman and Shen (1966)... 

The periodic integration of the original d5Uiamic DSC will result in a deconvoluted DSC heat flow signal, which is equivalent to the heat flow data obtained by traditional DSC. The subtraction of the component from the deconvoluted signal yields the kinetic component data. The Cp component gives information on reversible thermal events, such as Tg while the kinetic component provides data on the irreversible aspects of thermal transitions such as evaporation, decomposition, crystallization, relaxation, or curing. 

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