S. Nithiyanantham

Synthesis, Characterization and Effects of Citric Acid and PVA on Magnetic Properties of CoFe2O4

Cobalt ferrite (CoFe2O4) particles were synthesized by sol–gel method using metal nitrates, citric acid (CA) and polyvinyl alcohol (PVA). X-ray diffraction (XRD), high resolution scanning electron microscopy (HR-SEM), thermogravimetry/differential scanning calorimetry analysis and vibrating sample magnetometer were used to study the structural, thermal and magnetic properties of the CoFe2O4 powder. XRD results indicate that the resultant particles have crystalline, pure single phase spinel structure. From HR-SEM images, a systematic decrease in particle size is observed with an increase in PVA concentration, along with addition of CA. CA at various concentrations of PVA significantly enhance the magnetic properties of the materials.

Ultrasonic Investigation of Molecular Interactions in Binary Mixtures at 303 K

The ultrasonic velocity, density and viscosity at 303 K have been measured in the binary systems of toluene with benzene and o-xylone with benzene. The acoustical parameters such as adiabatic compressibility, free length, free volume and acoustical impedance are calculated. The results are interpreted in terms of molecular interaction between the components of the mixtures

Synthesis and characterization of nanophase zinc oxide materials

The substantial and intriguing applications in the field of optoelectronics, the fabrication of nano structure of ZnO based UV LEDs, FETs has been stalled because of the challenges/demand to put forth in the growth of highly stable, low resistive and high device performance. Growth of these Nano structure is difficult because of the self- compensating native donor defects, oxygen vacancies (Vo) and zinc interstitials (Zni) in the system. The n-type conductivity can be realized by doping with group III elements, and the band gap of ZnO lies in UV region and it can be used as UV detector. In presence of UV illumination, electrical conductivity increase due to generation of more charge carriers. In this present work, the authors to discuss the formation of pure and indium doped ZnO nanorods by chemical bath deposition.

Ultrasonic studies of polysaccharide (pectin) in aqueous media at 298.15 K

The ultrasonic velocity, density and viscosity of pectin in aqueous medium were measured at 298.15 K. The acoustical parameters such as adiabatic compressibility (β), free length (Lf), free volume (Vf), internal pressure (πi), acoustical impedance (Z), and relative association (RA), Rao’s constant (R) and Wada’s constant (W) are calculated. The results are interpreted in terms of molecular interaction between the components of the mixtures. Further, some more acoustical parameters such as relaxation time (τ), absorption coefficient (α/f2) and relaxation strength (r) are calculated with various percentage of pectin has been studied which reveals interaction between the solvent and the polymer (pectin) at various concentration of the polymer. The observed values suggested the solute-solvent interaction is favored.

Ultrasonic Study of Molecular Interactions in Binary Mixtures at 303 K

The ultrasonic velocity, density and viscosity at 303 K have been measured in the binary systems of 1,4-dioxane and acetone with water. From the experimental data, various acoustical parameters such as adiabatic compressibility (β), intermolecular free length (Lf), free volume (Vf), internal pressure (πi), Rao’s constant (R), Wada’s constant (W) and specific acoustical impedance (Z) were calculated. The results are interpreted in terms of molecular interaction between the components of the mixtures.

Acoustical studies on fructose with enzyme amylase in aqueous media at 298.15 K

Ultrasonic velocity (U), density (ρ), and viscosity (η) measurements have been carried out in three ternary mixtures of fructose with amylase in aqueous medium at 298.15 K. The experimental data have been used to calculate some derived parameters such as acoustical impedance (Z), relative association (Ra), Rao’s constant (RR), Wada’s constant (W), relaxation time (τ), relaxation amplitude (α/f2), relaxation strength (r), and some excess thermodynamical properties like excess adiabatic compressibility (βE), excess free length (LfE) excess free volume (VfE), excess internal pressure (πiE), and excess acoustical impedance (ZE). The above parameters have been evaluated and discussed in light of molecular interactions in the mixture.

Magnetic studies of nickel ferrite doped with rare earth ions

The magnetic properties nickel ferrites having general chemical formula NixFe(3 − x)O4 have been studied. The X-ray diffraction measurements confirmed the formation of a cubic spinel structure. The magnetic properties were studied by vibrating sample magnetometer (VSM). It exhibited lower coercivity and higher saturation magnetization due to high crystallinity. The saturation magnetization (Ms) and coercivity (Hc) for Nd and Gd are different ions since the magnetic moment of Gd3+ is greater than Nd3+.

Acoustical parameters of toluene + chloroform + cyclohexane mixtures at 303.15, 308.15, and 313.15 K

Ultrasonic velocity, density and viscosity of the ternary mixture of toluene + chloroform + cyclohexane, were measured at 303.15, 308.15, and 313.15 K. The thermodynamically parameters such as adiabatic compressibility (β), intermolecular free length (Lf), free volume (Vf), internal pressure (πi), acoustic impedance (Z), molar sound velocity (R), and molar compressibility (W) have been obtained from the experimental data for all the mixtures, with a view to investigate the exact nature of molecular interaction. Adiabatic compressibility and intermolecular free length decrease with increase in concentration and temperature. The other parameters show almost increasing concentration of solutes. These parameters have been further used to interpret the molecular interaction part of the solute and solvent in the mixtures.

Acoustical Studies on the Ternary Mixture of 1, 4- Dioxane

Ultrasonic velocity, density and viscosity of the ternary mixture of 1, 4dioxane + chloroform + cyclohexane, were measured at 303.15, 308.15 and 313.15 K. The thermodynamical parameters such as adiabatic compressibility (β), intermolecular free length (Lf), free volume (Vf), internal pressure (πi), acoustic impedance (Z), molar sound velocity (R) and molar compressibility (W) have been obtained from the experimental data for all the mixtures, with a view to investigate the exact nature of molecular interaction. Adiabatic compressibility and intermolecular free length decrease with increase in concentration and temperature. The other parameters show almost increasing concentration of solutes. These parameters have been further used to interpret the molecular interaction part of the solute and solvent in the mixtures.