Computational investigations of MnNiCuSb alloy for structural, elasto-mechanical and vibrational properties

摘要

The MnNiCuSb Quaternary Heusler Alloy (QHA) in Y-type I stable structure (cubic) is studied for structural, elastic, mechanical and vibrational properties by using Density Functional Theory (DFT). Three independent elastic constants C-11, C-12 and C-44 for this cubic system are computed with Generalized Gradient Approximation (GGA) functional. The mechanical parameters like Young's modulus, Shear and Bulk modulus, Pugh's ratio, Poisson's ratio, anisotropic factor, Cauchy pressure are then calculated by using these cubic elastic parameters. In addition, phonon dispersion curve and phonon density of states (PDOS) are computed with norm-conserving Martins-Troullier pseudo-potential in Perturbed Density Functional Theory. The phonon dispersion curve provides reststrahlen band 0.727 THz (Delta lambda = 412.065 mu m) for which material behaves as 100%. This value corresponds to Far Infra-Red (FIR) spectral region so this alloy can be used for manufacturing FIR-devices.