Elastic and Dynamical Properties of YB₄: First-Principles Study

We present the elastic and dynamical properties of YB₄ from first-principles calculations. It is found that the optimized lattice constants and bulk modulus (182 GPa) agree well with the experimental data. The structural stability of tetragonal YB₄ is confirmed by the calculated elastic constants and phonon spectra. YB₄ holds a Debye temperature of 874 K and has small elastic anisotropy. The estimated hardness of YB₄ is about 17 GPa, indicating that YB₄ is a hard solid while not a superhard one.