Current driven electrostatic ion cyclotron instability has been studied for parallel flow velocity shear with perpendicular a.c. electric field to the ambient magnetic field for bi-Maxwellian density drift distribution function. The method adopted for expression for dispersion relation and growth rate is kinetic approach and method of characteristic solution for ionospheric plasma. The effect of a.c. frequency, density gradient, and velocity shear scale length has been discussed.

In present paper, it is focused on theoretical study of TiO2 with particular emphasis on vibrational phonon properties by means of van der Waals three-body force shell model (VTBFSM). Present model includes van der Waals interactions (VWI) and three-body interactions (TBI) in the framework of both ion polarizable rigid shell model (RSM) with short-range interactions effective up to the second neighbor. The Coulombic ion–ion interaction contribution to the dynamical matrix is calculated by the Kellerman.1 Therefore, it may be inferred that the present model is the most realistic model for complete harmonic dynamical behavior of the crystals. The lattice dynamical study of phonon properties of transition metal titanium dioxide (TiO2) has been presented by means of VTBFS model. Titanium is an extremely light semiconducting material, exhibiting stable bcc structure in a certain temperature range 0–300 K normal pressures Debye temperature variation and combined density of states (CDS) of TiO2 has been studied in this work. At high temperature, strength and oxidation resistance of Ti alloys has improved. The model predictions are found to be in reasonable agreement with experimental data.2

In this communication, author is presenting ultrasonic and thermophysical properties of potassium fluoride (KF) and potassium chloride (KCl) by van der Waals three body force shell model with the help of second and third order elastic constants at 100 K–300 K. The elastic constants have been calculated by using Coulomb and Born– Mayer potential with the help of two parameters-distance of nearest neighbour and hardness parameter. We evaluated ultrasonic properties such as elastic constants, wave velocities, Debye temperature- average velocity, conductivity, and ultrasonic attenuation due to phonon–phonon interaction along in different direction [100], [110], and [111] orientations. The achieved results are hold good and are given very important information of these crystal for further investigation.

In this article author’s are reporting lattice dynamical properties of naphthalene (C10H8) by use of VTBFS model. we also report the combined density of states (CDS), dispersion relation and elastic properties of naphthalene. So, use of the present model the lattice property of naphthalene is reported successfully. Moreover, within our reported result the lattice modes exhibit more drastic changes in the structural and vibrational properties of naphthalene.

Abstract-Electrostatic velocity shear Kelvin-Helmholtz instability has been studied for bi-Maxwellian plasma in the presence of perpendicular a.c. electric field by using the method of characteristic solution. The effects of a.c. electric field temperature variation, velocity shear scale length, electron ion temperature ratio and other parameters on growth rate have been discussed.