First-Principles Study on the Structural, Elastic, Electronic and Vibrational Properties of Scandium Based Intermetalic Compounds (ScX, X = Co, Rh and Ir) Under Pressure

Abstract

The structural, electronic, mechanic and vibrational properties of B2-type scandium intermetallic compounds, ScCo, ScRh and ScIr, are studied by performing ab-initio density functional theory using the Vienna Ab initio Simulation Package (VASP). The exchange correlation potential within the generalized-gradient apraximation (GGA) of projected augmented plane-wave (PAW) is used. The calculated structural parameters, such as the lattice constant (a(0)), bulk modulus (B) and its pressure derivative (B) are calculated in the CsCl-(B2) structure. The electronic properties of the ScCo, ScRh and ScIr compounds are quantitatively analyzed using band structure and density of states (DOS). The electronic properties such as band structure and DOS reveal that considered scandium compounds are metallic in nature with large overlap at Fermi level. The elastic constants of these compounds are investigated using stress-strain method. Present results for elastic constants show that considered compounds are mechanically stable. Furthermore the effect of pressure on electronic properties and elastic constants are also investigated. The computed phonon dispersion curves show that these compounds are dynamically stable. The obtained results are compared with the available experimental and theoretical studies.