Elastic and Acoustic Properties of Heavy Rare-Earth Metals

Abstract

In this paper, ultrasonic properties like ultrasonic attenuation, sound velocities, acoustic coupling constants and thermal relaxation time have been studied in hexagonal structured metals Gadolinium (Gd), Terbium (Tb), Dysprosium (Dy), Holmium (Ho), Erbium (Er) and Thulium (Tm) along unique axis at room temperature. For the evaluations of ultrasonic properties, second-and third-order elastic constants have been computed also. The peculiar behavior of these metals is found at 55° due their least thermal relaxation time and highest Debye average velocity. Dy is more ductile, stable, perfect metal in comparison to other chosen metals due to its lowest value of attenuation. So we predict that Dy is most suitable lanthanide metals for material science and engineering.

Effect of temperature dependence ultrasonic velocities and attenuation of GaP nanowires

“…The combined effect of SOEC and density is reason for abnormal behaviour of angle dependent velocities. The nature of the angle dependent velocity curves in the present work is found similar as that for heavy rare-earth metals, laves-phase compounds, lanthanides metals and third group nitrides [14,17,22,29]. Thus the angle dependencies of the velocities in GaP nanowires are justified.…”

“…4). Since V D is calculated using V L , V S1 and V S2 [14,21], therefore the angle variation of V D is influenced by the constituent ultrasonic velocities. The maximum V D at 55°is due to a significant increase in longitudinal and pure shear (V S2 ) wave velocities and a decrease in quasi-shear (V S1 ) wave velocity.…”

“…Wave propagation velocity is another key factor in ultrasonic characterization, which in combination with attenuation can provide important tools in understanding, the inspectability of materials; for example, it can provide information about crystallographic texture. Ultrasonic velocity is directly related to elastic constants and the elastic constants, in particular, provide valuable information on the stability and stiffness of materials [14][15][16].…”

Viscosity variation of Cholesteryl oleyl carbonate at various temperature with Acoustic parametres

“…statistical mechanics provides a solid scientific basis to calculate viscosity of liquids.One of the useful approximate solutions of the statistical mechanical approach is due to Chapman [20], who characterized the force between the atoms in liquids by a distance parameter (the Goldschmidt atomic diameter, di) and a semi-empirical energy parameter (ei).Chapman showed that the reduced experimental viscosity data can be plotted as a function of the reduced temperature using a unique curve for all liquids. From figure 1 we have concluded that surface tension and viscosity are directly proportional to each other [5,6]. Figure 2 shows variation of surface tension and viscosity with temperature.…”

Non-destructive characterization of superionic conductor: lithium nitride

“…Ultrasonic attenuation is a very important physical parameter to characterize the material, which is well related to several physical quantities like thermal conductivity, specific heat, thermal energy density and higher order elastic constants [27]. The elastic constants provide valuable information about the bonding characteristics between adjacent atomic planes and the anisotropic character of the bonding and structural stability [28,29].…”