Prediction of dynamical, thermodynamic and mechanical properties of RuMnAs compound under hydrostatic pressure

The mechanical, dynamical and thermodynamical properties of the RuMnAs compound have been explored using the first-principle calculations under hydrostatic pressure. The sample material is stable in the FCC cubic phase verified by the elastic constants and positive cohesive energy up to a pressure of 15 GPa. The positive phonon frequency further strengthened the dynamical stability of the material in the cubic phase. The lattice constant of the system decreases linearly with the influence of pressure. The independent elastic constants (C11\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${C}_{11}$$\end{document} and C12\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${C}_{12}$$\end{document}), hardness of the material, ionic bonding and the ductility of the system increase almost linearly due to applied pressure. The thermodynamics study reflects that pressure has a negative effect on heat capacity, coefficient of thermal expansion and Gruneisen parameter in the examined compound, although Debye temperature increases with increased pressure.