Theoretical insights to elastic and thermal properties of WB4 tetraborides: A first-principles calculation

Abstract As an efficient tool for theoretical investigation, the first-principles calculation based on Density Functional Theory (DFT) has been applied to various fields of material development. In the present work, the first-principles calculation has been employed to predict the mechanic characteristics and thermal performances of three novel WB4 tetraborides. The single crystal constant Cij calculated by the stress-strain method shows that hP10-WB4 and hR15-WB4 tetraborides have stable crystal structures and elastic anisotropies. However, the calculated phonon dispersions reveal that hP20-WB4 is dynamically unstable. According to the calculated elastic modulus and anisotropy indexes A, the sequence of elastic anisotropy is hP10-WB4  hR15(640.517K), and the sound velocities have great anisotropy. Moreover, the calculated kmin shows the strong anisotropy and their values show the order: hP10 > hR15.