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The paper presents computation of second- and third-order elastic constants of Laves phase compounds ScOs2 and YOs2 at room temperature using Lennard-Jones potential model. The thermal relaxation time, ultrasonic velocity, ultrasonic attenuation and other related thermo-physical parameters (Debye average velocity, Debye temperature, thermal conductivity, specific heat and thermal energy density) are also calculated using second- and third-order elastic constants. The obtained elastic and ultrasonic properties of chosen compounds have been likened with the properties of other hexagonal structured materials for complete analysis and characterization. [ABSTRACT FROM AUTHOR]

The present article comprises computation of elastic, ultrasonic, and thermo-physical properties of RM (R = Tb, Dy, Ho, Er, Tm; M = Zn, Cu) compounds at 300 K. The second-order elastic constants (SOECs) and elastic moduli are evaluated initially, using potential model approach considering interaction up to second nearest neighbours. The ultrasonic velocities are obtained for wave propagation along <100>, <110>, and <111> crystallographic directions using evaluated SOECs. The Debye temperature, specific heat at constant volume, thermal energy density, thermal conductivity, and thermal relaxation time are also calculated. The obtained results are compared and analysed for justification and application of materials. [ABSTRACT FROM AUTHOR]

In present investigation, we studied the elastic, ultrasonic and thermal properties of SnAs, InTe and PbSb. The Coulomb and Born-Mayer potential model was utilized to compute the second and third order elastic constants up to second nearest neighbor. The direction dependent ultrasonic velocities for longitudinal and shear waves, Debye average velocity and mechanical constants such as bulk modulus, shear modulus, tetragonal modulus, Young's modulus, Poisson ratio, Pugh's indicator (shear modulus to bulk modulus ratio) and Zener anisotropy ratio were obtained with the use of the second order elastic constants and the density of the chosen materials. Since the Pugh's indicator is greater than 0.59 for all chosen materials, they have a brittle nature. Further the second and third order elastic constants with other associated acoustical parameters were used to compute the Debye temperature, thermal relaxation time, acoustic coupling constant and ultrasonic attenuation. The total ultrasonic attenuation is the smallest in the case of InTe along the <100> direction and highest for SnAs along the <111> direction. Thermo-elastic loss is insignificant in comparison to the loss due to the phonon-phonon interaction mechanism. Additionally, the thermal conductivity of these materials was found using Cahill's approach. The results of this investigation are discussed with the available findings and for other rock salt structured materials. [ABSTRACT FROM AUTHOR]

The ultrasonic attenuation in thulium monochalcogenides Tm X ( X=S, Se and Te) has been studied theoretically with a modified Mason’s approach in the temperature and range 100 K to 300 K along 〈100〉, 〈110〉 〈111〉 crystallographic directions. The thulium monochalcogenides have attracted a lot of interest due to their complex physical and chemical characteristics. TmS, TmSe and TmTe are trivalent metal, mixed valence state, and divalent semiconductor, respectively. Coulomb and Born-Mayer potential is applied to evaluate the second- and third-order elastic constants. These elastic constants are used to compute ultrasonic parameters such as ultrasonic velocities, thermal relaxation time, and acoustic coupling constants that, in turn, are used to evaluate ultrasonic attenuation. A comparison of calculated ultrasonic parameters with available theoretical/experimental physical parameters gives information about classification of these materials. [ABSTRACT FROM AUTHOR]

Organic–inorganic hybrid materials with nanoscale morphologies gain significant attention as a potential candidate for energy storage applications. Herein, nickel hydroxide (Ni(OH)2) and benzo[2,1,3]selenadiazole (BSe)‐capped dipeptide amphiphiles are electrodeposited over flexible nickel foam (NF) substrates to fabricate organic–inorganic nanohybrids. The in situ electrochemical deposition of organic–inorganic nanohybrids is investigated by Fourier transform infrared spectroscopy, X‐ray photoelectron spectroscopy, energy dispersive‐electron microscopy, and elemental mapping. The nanostructured morphology of the nanohybrid material is investigated by field‐emission scanning electron microscopy and transmission electron microscopy. The electrochemical performance and supercapacitor properties are examined in 1 m KOH aqueous solution. Aromatic diphenylalanine (FF)‐based nanohybrid BSeFF/Ni(OH)2 deposited on the NF electrode exhibit a specific capacitance of 1250 F g−1, whereas dileucine (LL)‐based nanohybrids BSeLL/Ni(OH)2 show a specific capacitance of 689 F g−1 at a current density of 2 A g−1. [ABSTRACT FROM AUTHOR]

Abstract: Crystalline CrO2 nanoparticles were synthesized using chemical methods. Nanofluids were synthesized by the dispersion of CrO2 nanoparticles in poly-vinyl pyrrolidone solution by an ultrasonicator. The structural properties of the nanoparticles were studied with the help of X-ray diffraction. The magnetic properties of the powdered CrO2 were measured with a vibrating sample magnetometer. The magneto-resistance and ultrasonic parameters of the nanofluid were characterized. The (a) effect of calcination temperature on crystalinity of CrO2 nanoparticles, (b) influence of sonication time on the nature of the magneto-resistance for the nanofluid, and (c) governing factor/mechanisms responsible to the ultrasonic properties are discussed. [Copyright &y& Elsevier]