Structural and mechanical stability of rare-earth diborides

ÖZIŞIK H., DELİGÖZ E., Colakoglu K., Surucu G.

CHINESE PHYSICS B, vol.22, no.4, 2013 (Peer-Reviewed Journal) identifier identifier

  • Publication Type: Article / Article
  • Volume: 22 Issue: 4
  • Publication Date: 2013
  • Doi Number: 10.1088/1674-1056/22/4/046202
  • Journal Name: CHINESE PHYSICS B
  • Journal Indexes: Science Citation Index Expanded, Scopus
  • Keywords: ab initio calculations, elastic properties, hardness, rare-earth diborides, INITIO MOLECULAR-DYNAMICS, TEMPERATURE HEAT-CAPACITY, ELASTIC-CONSTANTS, TRANSITION, SUPERCONDUCTIVITY, HARDNESS, RE


Structural and mechanical properties of several rare-earth diborides were systematically investigated by first principles calculations. Specifically, we studied XB2, where X = Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, and Lu in the hexagonal AlB2, ReB2, and orthorhombic OsB2-type structures. The lattice parameters, bulk modulus, bond distances, second order elastic constants, and related polycrystalline elastic moduli (e. g., shear modulus, Young's modulus, Poisson's ratio, Debye temperature, sound velocities) were calculated. Our results indicate that these compounds are mechanically stable in the considered structures, and according to "Chen's method", the predicted Vickers hardness shows that they are hard materials in AlB2- and OsB2-type structures.