Employing thermodynamical, optical and comprehensive dielectric studies, we have investigated a freshly synthesized chlorinated MHPOBC analogue antiferroelectric liquid crystal; it exhibits different chiral SmC sub-phases, viz. SmCα*, SmC* SmCγ*, at considerably lower temperature in comparison with MHPOBC, wide range room SmCA* phase. Dielectric spectroscopy investigations under planar molecular anchoring were carried out the frequency 1 Hz to 10 MHz. The data measured for low high regions...

The electrical properties of frustrated twist grain boundary (TGB) phase are a matter curiosity. Some studies have indicated the existence soft and Goldstone modes in TGBA TGBC* phases respectively. However, experimental results still not very conclusive. In present work, we report dielectric wide temperature range an optically active dimeric compound 4‐n‐decyloxy‐4′‐(cholesteryloxycarbonyl‐1‐butyloxy) chalcone frequency 1 Hz to 35 MHz for planar homeotropic anchoring molecules. Two...

We describe dipolar nematic colloids comprising mutually bound solid microspheres, three-dimensional skyrmions, and point defects in a molecular alignment field of chiral liquid crystals. Nonlinear optical imaging numerical modeling based on minimization Landau--de Gennes free energy reveal that the particle-induced skyrmions resemble torons hopfions, while matching surface boundary conditions at interfaces crystal colloidal spheres. Laser tweezers videomicroscopy skyrmion-colloidal hybrids...

Dielectric spectroscopy of two room temperature chiral liquid crystal mixtures (W-96 and W-97) have been carried out in the frequency range 100 mHz–10 MHz. Low dielectric relaxation modes corresponding to collective behavior molecules (Goldstone- soft-modes) SmC* phase found be masked by ionic conductance. Two slow due conductance detected (below 15 Hz) planar-aligned samples. It has observed that effect decreases with number thermal annealing cycles on materials. With large it possible wipe...

Abstract Fe‐rich relict olivine grains are found in a small percentage of cosmic spherules, which studied here to determine the nature their precursors. We examined 128 with Fa >10 mol% from 53 spherules different types collected Antarctica (Antarctica micrometeorites [AMM]) and deep‐sea sediments (DSS) Indian Ocean. olivines identified close analogs type II chondrule formed early solar system. The analysis shows well‐defined trends molar Fe/Mn versus Fe/Mg an affinity for ordinary...

The present long-term study has been conducted with dual objectives: firstly, to monitor the spatio-temporal variation of ambient air quality parameters and secondly, evaluate impact pollutants on Delhi population.

The investigated optically active dimeric compound, 4-n-undecyloxy-4'-(cholesteryloxycarbonyl-1-butyloxy)chalcone, shows wide temperature ranges of two twist grain boundary (TGB) phases, TGBA and TGBC*. Comprehensive dielectric studies have been carried out for this compound in the frequency range 1 Hz–10 MHz different conditions molecular anchoring. This negative anisotropy (). Various electrical parameters, namely permittivity, anisotropy, DC conductivity activation energy, determined...

Temperature and bias electric field-dependent dielectric behaviour of an antiferroelectric liquid crystal compound was investigated in the frequency range 1 Hz to 10 MHz. The possessed paraelectric (SmA*) () phases, addition a monotropic hexatic smectic phase. study showed presence soft mode SmA* In phase, two weak relaxation modes were observed for planar orientation molecules. These related ordering helical structure Two modes, order also characterized terms bond-orientational coupling...

Abstract Micrometeorites (MMs) are extraterrestrial dust particles, in the size range of tens µm to mm, recovered from Earth’s surface primarily deep‐sea sediments, Antarctica, and also space. The present collection MMs (>50 µm) obtained by melting ~50 t ice near Maitri station, has allowed us investigate abundance properties particles an unbiased technique. reveals a large quantity material ~80−140 range. Previous collections have shown at diameter ~200 µm, which is contrast our...

The binary mixtures of Di-heptyloxyazoxybenzene (HOAB) and Cholesteryl Benzoate (ChB) show the longest ever temperature range TGBA TGBC* phases for ChB concentration 25 18 mole percent respectively. Comprehensive dielectric studies these two have been carried out in frequency 1 Hz to 10 MHz different condition molecular anchoring. Both negative anisotropy (Δ ϵ′ = ϵ‖′−ϵ⊥′ < 0) all mesophases. One mode relaxation showing Arrhenius behavior has detected N*, homeotropic aligned sample both...