Enhanced dielectric and electro-optical properties of a newly synthesised ferroelectric liquid crystal material by doping gold nanoparticle-decorated multiwalled carbon nanotubes

In this article, a newly synthesised ferroelectric liquid crystal (FLC) material, namely LAHS 22, has been characterised. The characterisation of the FLC material has been performed using dielectric relaxation spectroscopy, differential scanning calorimetry and polarisation optical microscopy. We observed an enhancement in the dielectric and electro-optical properties of the FLC material by incorporating gold nanoparticles (GNPs)-decorated multiwalled carbon nanotubes (MWCNTs). The GNPs-decorated MWCNTs cause an increment in dielectric dispersion (up to kHz), absorption, spontaneous polarisation and rotational viscosity of the FLC material. The pure and GNPs-decorated MWCNTs doped FLC cells were analysed by means of various dielectric spectroscopic and optical measurements. The observed enhancement in the dielectric and electro-optical properties of the FLC material has also been studied with concentration of GNPs-decorated MWCNTs in FLC material. The GNPs-decorated MWCNTs/FLC composites are not only of fundamental importance, but also useful materials for device applications such as liquid crystal displays and memory devices.     

Luminescence in Ca1−xYxF2+x

Some compounds with fluorite structures in the system CaF₂–YF₃ were prepared by precipitation followed by thermal annealing at 1000 °C. Photoluminescence spectra of Ce³⁺ and Eu²⁺ were studied. In this host, Ce³⁺ exhibits PL, which is totally different from that observed for the constituent fluorides. Eu²⁺ emission, on the other hand, is almost the same as that for CaF₂. The changes are explained in terms of the defect structure of Ca_1?xY_xF_2+x.     

An Entire Function Defined by a Nonlinear Recurrence Relation

For the nonlinear recurrence relation it is proved that the limit exists and defines an entire function of ₂ = ₁(1-₁).     

Improved equivalent circuits for acoustic plate wave devices

This paper presents improved equivalent circuits for the analysis and design of acoustic plate wave devices. The method uses a mixed equivalent circuit for the interdigital transducer consisting of both active and passive sections placed on the surface of a piezoelectric plate. The values of the various circuit elements are obtained by carrying out a best fit between theoretical and experimental frequency dependence of the real and imaginary parts of transducer input impedance. Knowledge of the equivalent circuit parameters allows one to optimize design of the devices. The method has been successfully employed for the design of one-port shear-horizontal wave resonators on Y-X lithium niobate plates. The proposed method can also be utilized for determining acoustic wave velocity with high accuracy.     

The third and fourth spectra of gallium: Ga III and Ga IV

The third and fourth spectra of gallium have been photographed in the region 6000–400 Å by using a 3-m normal-incidence, vacuum spectrograph and a 3.5-m Ebert spectrograph. A three-electrode vacuum spark and a spark in helium were used as sources. New measurements for the wavelengths have confirmed earlier work and provided material to extend the analysis of Ga III and Ga IV.     

Visible green emission of Ho3+ and Er3+ in tellurite glass

Characteristic visible green emission of Ho³⁺ and Er³⁺ was observed in zinc tellurite glass. Multiphonon relaxation theory was quantitatively applied to explain the experimentally obtained results. Fluorescence assignments and lifetime measurements have also been made.     

Study of the traps created in the single crystal of CdSe by the irradiation of Mo K α X-ray quantum

Traps were created in the single crystal of CdSe by bombardment with Mo Kα X-ray radiation. These traps were studied by the relaxation curves of photoconductivity, obtained at 6000 Å and after two dosages of radiation. It has been found out that the traps created were β-type.     

Thermodynamic properties of some monomeric compounds in the standard ideal gas state

Thermodynamic functions of ten monomeric compounds have been calculated for three temperatures by the statistical method using molecular structural data and vibrational assignments. The ideal gas state entropies at 298.15°K are: maleic anhydride, 71.9; β-propiolactone, 69.1; vinylene carbonate, 70.1; cyclopentadiene, 65.3; diketene, 72.3; cyclopropene, 58.7, vinyl fluoride, 60.4; ethyleneimine, 62.8; butatriene, 71.7; and carbon suboxide, 66.0 cal./deg-mole. The standard free energies and equilibrium constants of formation are also derived by using mostly the published data on the heats of formation of these monomers.