Dielectric isotropy

In these calculations, the isolated defect or defect cluster is embedded in the crystal, which extends to infinity, and the contrast between this approach and that used in the supercell methods is illustrated diagrammatically in Figure 1. The normal procedure in a Mott-Littleton calculation is to relax all the atoms in a region of crystal surrounding the defect, containing typically 100-300 atoms, until all are at zero force. Newton-Raphson minimization methods are generally used. The relaxation of the remainder of the crystal is then described by more approximate methods in which the polarization, P at a point r, is calculated for crystals that have dielectric isotropy, from the expression ... 

For low molecular liquid crystals the temperature dependence of fQ - the frequency of dielectric isotropy derived from dielectric... 

Support for the inter-lamellar shear hypothesis is provided by the isotropy of the dielectric / process, which shows that the mechanical anisotropy cannot be a consequence of an ordered inter-lamellar material. 

Isotropy of piezoelectric ceramics is destroyed during poling process but remains in the direction perpendicular to the poling field direction. Stractuie of tensor material coefficients of oomm cylindrical polar symmetiy is the same as for the hexagonal 6mm symmetry for dielectric, piezoelectric and elastic tensors. 

The two-dimensional model [66] of this domain structure shows that its threshold considerably depends on the value of the Leslie viscosity coefficient as and the dielectric anisotropy Ae. Unlike the Kapustin-Williams domains, this instability could also be observed for negative conductivity anisotropy. There remains only one specific point where the instability ceases to exist, namely, the conductivity isotropy point. Act = 0. 

The nanostructured FSS consists of a dielectric matrix (polymeric or silicone resin) with micro- and nanoparticles embedded into it. For this composite nanostmctured material, it is required to have isotropy, homogeneity and continuity properties. In fact, when the nano-FSS works at high frequency. 

By simple superposition of the dielectric tensors of the uniaxial arms, which are linked together with opening angle it was shown [48] that the anticlinic antiferroelectric state is optically isotropic if the tilt angle is 0 = 45° and = 109.5° Actually for the experimentally studied material the angles are 0 = 47° and O 106°, which results fairly good optical isotropy. (Note that anticlinic ferroelectric SmC Ps states can also be optically isotropic if the 0 = 45° and = 109.5°condition is fulfilled.)... 

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