We report on photorefractive composites composed of poly~N-vinyl carbazole! ~PVK!/liquid crystal/C60 with PVK of different molecular weight ~MW!. The influence of MW on the photorefractivity was studied. The results show that a higher MW leads to a larger two-beam coupling coefficient G and a larger effective electric–optical coefficient. G over 200 cm is observed for the composite based on the...

3 Ground states of the 2D system in a strong magnetic field 8 3.1 The integral quantum Hall effect (IQHE) . . . . . . . . . . . . . . . . . . . 8 3.2 Electron-electron interaction and the fractional quantum Hall effect (FQHE) 10 3.3 Composite Fermions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 3.4 The Wigner crystal state . . . . . . . . . . . . . . . . . . . . . . . . . ....

Birefringence, arising from locally preferred orientation of molecules or functional groups in polymeric and relatedmaterials has been observed in a near-field scanning optical microscope (NSOM) at suboptical spatial resolution. Our observations were successfully correlated to existing structural models of the samples, demonstrating the utility of birefringence observations in NSOM. We present ...

We report here the first synthesis of mesoscopic, monodisperse particles which contain nanoscopic inclusions of ferromagnetic cobalt ferrites. These monodisperse ferromagnetic composite particles readily self-assemble into magnetically responsive photonic crystals that efficiently Bragg diffract incident light. Magnetic fields can be used to control the photonic crystal orientation and, thus, t...

In this paper, we present an overview of recent progress in the development of the NASA Macro-Fiber Composite (MFC) piezocomposite actuator device. This will include a brief history of the development of the MFC, a description of the standard manufacturing process used to fabricate MFC actuators, and a summary of ongoing MFC electromechanical characterization testing. In addition, we describe t...

We demonstrate that when an optically birefringent nematic liquid crystal is infiltrated into the void regions of an inverse opal, photonic-band-gap (PBG) material, the resulting composite material exhibits a completely tunable PBG. In particular, the three-dimensional PBG can be completely opened or closed by applying an electric field which rotates the axis of the nematic molecules relative t...

By using soluble fullerene derivative [60]PCBM, we improved photorefractive efficiency in polymer-liquid crystal composites in comparison to previous works on similar materials. We show the effect of polymer network results in resolution and bandwidth improvements compared to pure liquid crystals. This is explained by the introduction of a charge trapping mechanism, providing a memory effect fo...

In this study, a simple hot-injection method to synthesize high-quality inorganic perovskite cesium lead iodide (CsPbI3) quantum-dots (QDs) was demonstrated. Adding CsPbI3 QDs into the organic methylamine triiodide (CH3NH3PbI3) form composite film, annealed by different temperatures, found be effectively enhanced crystallization. The intensity of preferred peak (110) MAPbI3 increasing size crys...

The photorefractivity of a photorefractive composite consisting of poly(N-vinylcarbazole) (PVK) doped with a non-room-temperature liquid crystal, 4-butyloxy4’-cyanobiphenyl (4OCB), and C60 was studied by means of measuring the two-beam coupling coefficients. The results show that the photorefractivity is enhanced by phase separation. PACS: 42.65; 61.30; 61.40 Interest in materials that exhibit ...