Computational Study of Ultrasonic Parameters of Hexagonal Close-Packed Transition Metals Fe, Co, and Ni

Abstract

The ultrasonic properties like ultrasonic attenuation, sound velocity in the hexagonal closed packed (hcp) Fe, Co and Ni have been studied along unique axis at room temperature. The second- and third order elastic constants have been calculated for these metals using Lennard-Jones potential. The velocities VL and VS1 have minima and maxima respectively, with 45° with the unique axis of the crystal, while VS2 increases with the angle from unique axis. The inconsistent behavior of angle dependent velocities is associated to the action of second order elastic constants. Debye average sound velocities of these metals are increasing with the angle and has maximum at 55° with unique axis at room temperature. Hence when a sound wave travels at 55° with unique axis of these metals, then the average sound velocity is found to be maximum. The comparison of calculated ultrasonic parameters with available theoretical/experimental physical parameters gives information about classification of these metals.