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The incorporation of heteroatoms in the chemical structure of organic molecules has been identified as analogous to the doping process adopted in silicon semiconductors to influence the nature of charge carriers. This strategy has been an eye‐opener for material chemists in synthesizing new materials for optoelectronic applications. Phenanthro[9,10‐a]phenazine‐based mesogens have been synthesized via a cyclo‐condensation pathway involving triphenylene‐based diketone and o‐phenyl diamines. The incorporation of phenazine moiety as discussed in this paper, alters the symmetric nature of the triphenylene. The phenanthro[9,10‐a]phenazine‐based mesogens exhibit hole mobility in the order of 10−4 cm2/Vs as measured by the space‐charge limited current (SCLC) technique. The current density in the SCLC device increases with increasing temperature which indicates that the charge transport is associated with the thermally activated hopping process. This report attempts to elucidate the self‐organization of asymmetric phenanthro[9,10‐a] phenazine in the supramolecular liquid crystalline state and their potential for the fabrication of high‐temperature optoelectronic devices. However, the low charge carrier mobility can be one of the challenges for device performance. [ABSTRACT FROM AUTHOR]

5CB liquid crystal (LC) is a well-studied material for a variety of applications due to its orientational ordering and viscosity. LCs mostly suffer from ionic impurities which can be filtered using metal oxide nanoparticles. Beyond this conventional role of TiO2 nanoparticles (NPs) in ionic impurity filtration in LCs, we have employed a new methodology to improve the planar orientation of 5CB molecules by depositing a thin layer of NPs on either side of the ITO electrode. The 5CB LC exhibits a typical birefringent schlieren texture; however, the presence of TiO2 layer alters the molecular orientation. On the TiO2 surface, the 5CB LC molecules showed schlieren defect points characterised by both twofold (s = $ \pm $ ± 1/2) and fourfold (s = $ \pm $ ± 1) brush-like structures. The change in texture and lowering of dielectric permittivity might be attributed to the change in the pretilt angle of 5CB molecules owing to the mutual interactions between 5CB and TiO2 layer. Remarkably, the 5CB LC within the TiO2-coated cell attains the isotropic phase at lower temperature as compared to the cells coated with polyimide SE-130. The underlying mechanism for coarsening kinetics in the 5CB is elucidated using the Lifshitz-Slyozov-Wagner (LSW) theory. [ABSTRACT FROM AUTHOR]

High‐resolution Sr and Nd isotope compositions along with major and trace element abundances have been analyzed in silicate fraction of sediments core, SSD004‐GC03, from the Equatorial Indian Ocean (7.2°N and 77.9°E) at 1,540 m water depth with a depositional history of ∼38 ka to determine source variabilities and their controlling factors. 87Sr/86Sr (0.71978–0.72491), ƐNd (−14.8 to −21.9), and a couple of source diagnostic elements display profound variability over the depositional time scale and point toward major sediment contribution from the Peninsular Gneissic Complex (PGC) and the Deccan Basalts along with aeolian dust flux, their relative proportions being determined by climate variability. The cold/arid periods are characterized by an enhanced proportion of aeolian dust and the Deccan Basalts, whereas the sediment contribution from the PGC is augmented during the warm/humid periods. The sediment provenance variations at the Equatorial Indian Ocean coincide very well with known cold/arid (Heinrich Stadial events: HS 1–4, LGM, Younger Dryas, 8.2 ka, 5.2 ka, and 1.1 ka) and warm/humid (Early Deglacial, Holocene Intensified Monsoon) climatic events reported in the tropical region and sea‐level change which are strongly captured by the Sr‐Nd isotope and elemental composition of sediments. The present investigation underscores the significant role of climate, mainly the aridity, in modulating the dust fluxes and erosion intensity and the strong coupling between Indian monsoon and North Atlantic climatic oscillations and further demonstrates minimal time delay between the production and transport of sediment from source to sink. Key Points: High‐resolution 87Sr/86Sr, ƐNd and a few diagnostic elements track temporal variation of sediment sources in the Equatorial Indian OceanThe cold periods are characterized by enhanced proportions of aeolian dust and the Deccan Basalts, whereas the PGC dominates warm periodsNorth Atlantic climatic oscillations modulate Indian monsoon thereby controlling dust and erosional fluxes in the Equatorial Indian Ocean [ABSTRACT FROM AUTHOR]

We represent a detailed study of a dilute suspension of ferroelectric barium titanate nanoparticles (BaTiO3 NPs) in a nematic matrix by probing dielectric, electro-optical, and optical properties. The strong local surface electric field (order of ∼1010 Vm−1) of BaTiO3 produces pseudonematic domains within the matrix, which renders an enhancement in both the perpendicular and parallel components of dielectric permittivity that increases with increasing NP concentrations. Due to changes in molecular ordering, the dielectric anisotropy of pristine nematic increases by 10.7%, 24.6%, and 33.3% after the addition of 0.1, 0.3, and 0.5 wt. % BaTiO3 NPs with subsequent lowering in threshold voltage. Interestingly, the nematic-BaTiO3 blended cells showed 23.2%, 49.3% and 67.6% faster electro-optic response for 0.1, 0.3, and 0.5 wt. % of NPs, respectively. In the nematic matrix, BaTiO3 NPs act like chromophores resulting in a bathochromic shift in fluorescence spectra due to an enhanced degree of conjugation. This investigation reveals that the ferroelectric BaTiO3 NPs-nematic composites will be suitable for superior fluorescent electro-optical devices. [ABSTRACT FROM AUTHOR]

A unique gyroid cubic phase has been discovered for a discotic star mesogen with three covalently attached DNA bases. In this cubic Ia3‾d ${Ia\bar{3}d}$ phase, the conjugated core of the mesogens and the thymine pseudo guests self‐assemble in mirror image continuous networks, representing a semiconducting material with three‐dimensional transport pathways. The hole carrier mobilities are found to be in the typical range of poly(phenylenevinylene) scaffolds. This structure is stabilized by a weak hydrogen bonding between the thymine bases and can be switched to a columnar liquid crystal – thermally and by the addition of complementary adenine guests. [ABSTRACT FROM AUTHOR]

Four new room-temperature nematic liquid-crystalline (LC) dimers consisting of a wedge-shaped 3,4,5-tridecyloxy gallic ester molecule linked to either cyanobiphenyl, cholesteryl, pentaalkynylbenzene or triphenylene based moieties are reported. Dimers with pentaalkynylbenzene and triphenylene moieties in their room-temperature discotic nematic (ND) mesophase show ambipolar charge carrier mobilities of the order of 10−5 cm2 V−1 s−1 and 10−3 cm2 V−1 s−1, respectively, as measured using a time-of-flight (ToF) technique. [ABSTRACT FROM AUTHOR]