Materials with High Optimal Anisotropy

As described in Sec. 3.1.22 and 3.1.4.2 it is essential to adjust the birefringence. An, for a given cell gap, d, to achieve an optimal display performance. Since the switching time, T, strongly depends on d (Eqs. 19 and 20) materials with high An are required. 

The refractive indices n, Hq) of liquid crystals are determined by the molecular po- 

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Much higher temperatures are achievable for SmCo5 and other highly anisotropic materials. However, typical hard-magnetic materials have temperature-dependent anisotropies that are maximized at or above room temperature [16, 77]. Little work has been done to optimize anisotropies at low temperatures, although it is known that some compounds with Tc < 300 K have huge anisotropies of 100 to 1000 MJ/m3 [83, 208],... 

Figure 2. Effect of piezoelectric anisotropy on the single-crystal orientational behavior. Left inset embodies the polar response of the normalized piezoelectric behavior for different anisotropy factors. Note that the optimal orientation changes as the degree of anisotropy increases. Left inset shows the optimal orientation of each single-crystal, as a function of crystallographic anisotropy. Note that contrary to what it is intuitively expected, in the limit of high anisotropy, A 2/3, the crystallographic orientation at which highest piezoelectric strains will occur will asymptotically align with the direction of the applied field. Furthermore, the optimal orientation for materials with weak anisotropy will asymptotically converge to 0=54.16°.

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