An ab initio study of spectroscopic and thermodynamic characteristics of MgH2 and TiC systems. (8th March 2019)

• Record Type: Journal Article
• Authors: Arif Khalil, R.M.; Hussain, Fayyaz; Imran, Muhammad; Rasheed, Umbreen; Rana, Anwar Manzoor; Murtaza, G.
• Is Part Of: International journal of hydrogen energy. Volume 44:Number 13(2019)
• Page Start: 6756
• Page End: 6762
• Publication Date: 2019-03-08
• Subjects: Lattice dynamics -- Hydrogen release temperature -- Harmonic approximation -- Density functional theory -- Thermodynamics; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2019.01.198
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: In this investigation, structural, dynamical and thermodynamic characteristics of magnesium hydride (MgH2 ) and titanium carbide (TiC) are performed through first principle calculations based on the density functional theory (DFT). The lattice dynamics were investigated using the finite displacement supercell approach and thermodynamic calculations were carried out using the harmonic approximation. The modes of vibrations were studied to explore the behavior of individual atoms. The minimum hydrogen release temperature was noted to be Tc = 719 K when only electronic and vibrational free energies of MgH2 and TiC systems are considered at pressure of 1 bar. However, a remarkable reduction in hydrogen release temperature is noticed in MgH2 and TiC system i.e. Tc = 321 K (fall of 398 K) by including all the contributions of free energies (i.e. electronic, translational, rotational and vibrational) of hydrogen molecule. Highlights: Structural and Vibrational properties of TiC, Mg and MgH2 systems. Modes of Vibrations for TiC and MgH2 systems. Free energy calculations of Mg, MgH2 and TiC system. Hydrogen release temperature in MgH2 system.