Doping dynamic scattering

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... 

Y. Ohnishi and M. Ozutsumi, Properties of Nematic Liquid Crystals Doped with Hydroquinine and p-Benzoquinone Long-term Dynamic Scattering Under DC Excitation, Appl. Phys. Lett., 24, p. 213 (1974). 

In LSCO, the basic evidence of (dynamic) stripes comes in the form of the well-known four-fold splitting of magnetic (7r, n) peak, which is observed by inelastic neutron scattering[l], and corroborated by the observation of the elastic response with similar peak pattern in Nd-doped LSCO[2], The above fourfold splitting has been generally interpreted in the stripe community as the... 

F. Fillaux, C. Cachet, S.F. Parker, J. Tomkinson, A. Quivy L.T. Yu (2000). J. Electrochem. Soc., 147, 4184—4188. Inelastic neutron scattering smdies of the proton dynamics in bi-doped manganese oxides. 

B. Francois (1997). Synth. Met., 84, 941-942. Dynamics of pristine and doped conjugated polymers A combined inelastic neutron scattering and computer simulation analysis. 

The existence of I5 anions in heavily doped, well-oriented samples has been questioned at times, when very similar data are interpreted by different investigators [74,134]. From a study of the temperature dependence of the diffraction and the effects of aging, Albouy el a/. [121] have concluded that the scattering of well equilibrated samples can be described on the basis of I3 anions only. Aging involves the release of I2 under ambient conditions, a process which can be enhanced by dynamic evacuation (pumping) and which also proceeds much more rapidly under irradiation. Thermal expansion in relation to conductivity has been explored by Halim et al. [135]. 

In 1991, Basche and Moerner included perylene in polyethylene [71]. The small and rigid perylene molecule has good emission and triplet properties, but absorbs in a difficult spectral region, around 445 nm. Because the spectral jumps we discuss here are mainly consequences of matrix dynamics, we must shortly discuss sample preparation. The samples of [71] were made from low-density polyethylene (crystallinity 25%), doped at low concentration with perylene, and were quickly quenched from the melt to liquid nitrogen temperature to reduce light scattering. The thin films thus obtained were 10 to 20 pm thick. The polymer structure is thus expected to be dominantly amorphous. 

---