Ultrasonic Grüneisen parameters of plutonium monopnictides

Abstract

The Born–Mayer and Coulomb potential has been utilized to figure out higher order elastic constants for the plutonium monopnictides PuPn (Pn: N, P, As, Sb, Bi) in the temperature interval 100–500 K. The mechanical constants have been calculated using the Voigt–Reuss–Hill (VRH) approximation at room temperature using the second order elastic constants. The Born stability conditions have been found out for finding the nature and strength of PuPn. The first order pressure derivatives of second order elastic constants and mechanical properties have been computed with the help of second- and third-order elastic constants in the temperature interval 100–500 K. The second order elastic constant and density has been used to obtain the ultrasonic velocities for longitudinal and shear modes of propagation and the Debye average velocity along < 100 > , < 110 > and < 111 > directions in the temperature span 100–500 K. Finally, the ultrasonic Grüneisen parameters of PuPn have been enumerated along < 100 > , < 110 > and < 111 > directions at room temperature. Evaluated results have been discussed and correlated with applicable data of similar type materials.