Dope anisotropy

Al, N, B, Ga and P solubilities in 6H have shown a crystal face dependence [1], For Al, Ga and B the solubility limit is smaller on the [0001 ]C face. For P and N the solubility limit is smaller on the [0001]Si face. Vodakov et al [1] suggest that this dependence is caused by the very strong orientation doping anisotropy of 6H-SiC. The data for Al, B and Ga showed very good agreement when measured by the neutron-activation method and electrophysical measurements employing the Hall effect. The dependence on crystal direction of the solubility for N, B, Al, Ga and P in 6H-SiC is listed in TABLE 1. The maximum solubility limits for many of the impurities in 6H-SiC are listed in TABLE 2. 

EFFECT OF DOPE ANISOTROPY ON AS-SPUN PROPERTIES OF AROMATIC POLYAMIDE FIBRES... 

Chromophores with a rather high optical anisotropy are the merocyanines (77), especially in the cyanine limit with equal contributions of the apolar and zwitterionic resonance structures [319]. Thus, they also have been proposed as promising candidates for photorefractive systems based on molecular glasses. For 77, doped with a photosensitizer, a refractive index modulation of 0.01 at an electrical field of 22 V/pm was reported. 

Dynamic scattering displays, which are the first generation LCDs, make use of a nematic LC with a negative dielectric anisotropy (As = — <0) doped with an... 

Their measurements revealed no significant change of the dielectric anisotropy at the same reduced temperatures (TIso/N — T), which our group was able to confirm in related experiments using mixtures of 5CB doped with hexanethiol-capped gold nanoparticles [298]. 

Based on their thermal properties, polymeric and glassy molecular PR materials can be classified as high-7 and low-7), materials. The Tg values of polymer composites can be lowered by doping small molecules as plasticizer. Introduction of a long alkyl side chain can effectively reduce the Tg of fully functionalized polymers. The glassy molecular materials usually possess low Tg if they are amorphous. For the high-7 and low-7), materials, the figures of merit of the NLO chromophores are defined by Eqs. (35) and (40), respectively. The latter are obviously enhanced by contributions from the polarizability anisotropy of the NLO chromophore. 

The motivation of this study was to establish a relationship between the structure of the films and their electrical and optical characteristics, which strongly depend on the indium concentration [11, 20], The conclusion of this study is clearly beyond the scope of this review. But the polarized EXAFS study has clearly evidenced that the indium doping affects the grain growth process by increasing the surface anisotropy of films. Finally this example shows that we have powerful experimental but also theoretical tools to study surfaces or oriented systems. 

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