Elastic and acoustic properties of nanocrystalline Ni and Mg-doped hexagonal close-packed Ni nanoparticlesAuthor(s): Pramod KumarYadawa
The ultrasonic properties like ultrasonic sound velocity in the hexagonal closed packed (hcp) nanocrystalline Ni and Mg-doped hcp Ni nanoparticles have been studied along unique axis at room temperature. The second- and third order elastic constants (SOEC & TOEC) have been calculated for these nanoparticles using Lennard ÂJones potential. The velocities VL and VS1 have maxima and minima respectively with 45ï° with unique axis of the crystal, while VS2 increases with the angle from unique axis. The inconsistent behaviour of angle dependent velocities is associated to the action of second order elastic constants. Debye average sound velocities of these nanomaterials are increasing with the angle and has maximum at 550 with unique axis at room temperature. Hence when a sound wave travels at 55ï° with unique axis of these nanomaterials, 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 nanomaterials.