FP-LMTO investigations of mechanical stability and high pressure of platinum nitride compounds

• Published in: Solid state communications 2009-06, Vol.149 (23), p.941-945
• Main Authors: Rabah, M., Rached, D., Khenata, R., Moulay, N., Zenati, A.
• Format: Article
• Language: English
• Subjects: A. Super hard materials; B. FP-LMTO; C. High pressure; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; D. Ground state; Elasticity, elastic constants; Electron density of states and band structure of crystalline solids; Electron states; Equations of state, phase equilibria, and phase transitions; Exact sciences and technology; Mechanical and acoustical properties of condensed matter; Mechanical properties of solids; Other inorganic compounds; Physics; Solid-solid transitions; Specific phase transitions
• ISSN: 0038-1098; 1879-2766
• DOI: 10.1016/j.ssc.2009.03.023

We report local density functional calculations using the full potential linear muffin-tin orbital (FP-LMTO) method for binary platinum nitride (PtN), in five different crystal structures, the rock salt (B1), zinc-blende (B3), wurtzite (B4), nickel arsenide (B8), and PbS (B10) phases. The ground state properties such as the equilibrium lattice constant, elastic constants, the bulk modulus and its pressure derivative of PtN in these phases are determined and compared with the other available experimental and theoretical works. Our calculations confirm in the B3 structure that PtN is found to be mechanically stable with a large bulk modulus B=232.45 GPa and at a sufficiently high pressure the B8 1 structure would be favoured. The theoretical transition pressure from zinc blende (B3) to NiAs (B8 1), zinc-blende (B3) to rock-salt (B1) and zinc-blende (B3) to PbO (B10) is determined to be 9.10 GPa, 9.85 GPa and 69.35 GPa, respectively. Our calculation shows also in five different structures for PtN a high bulk modulus is a good indicator of a hard material.