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High pressure phase transitions and physical properties of Li2MgH4 implications for hydrogen storage       
Yazarlar
Selgin Al
İzmir Demokrasi Üniversitesi, Türkiye
Doç. Dr. Cihan KÜRKÇÜ Doç. Dr. Cihan KÜRKÇÜ
Kırşehir Ahi Evran Üniversitesi, Türkiye
Çağatay Yamçıçıer
Özet
A systematic calculation has been performed in order to study phase transitions and hydrogen storage properties of ternary hydride Li2MgH4 under pressure. The structural, elastic, electronic and vibrational properties of Li2MgH4 are collected by means of density functional theory. There are three phases identified; Pbam at 0 GPa, Pnma at 5 GPa and Pna2(1) at 65 GPa Pbam and Pnma phases of Li2MgH4 are found to be mechanically and dynamically stable. Ductility of the phases are determined based on Pugh's criteria. It is found that Li2MgH4 becomes ductile at 5 GPa, otherwise it is a brittle material. Electronic band structures and corresponding partial density of states of phases are also obtained. All phases at 0 GPa, 5 GPa and 65 GPa have wide band gaps, indicating that Li2MgH4 is an insulator at all pressures. The phonon dispersion curves of Pbam and Pnma phases have no imaginary frequency indicating that both phases of Li2MgH4 are dynamically stable. The gravimetric hydrogen density of Li2MgH4 is calculated as 10.52 wt %, which is a great rate along with the hydrogen desorption temperature of 670 K. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
Anahtar Kelimeler
Computational method | Electronic properties | Solid state hydrogen storage | Ternary hydrides
Makale Türü Özgün Makale
Makale Alt Türü SSCI, AHCI, SCI, SCI-Exp dergilerinde yayımlanan tam makale
Dergi Adı INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
Dergi ISSN 0360-3199
Dergi Tarandığı Indeksler SCI-Exp, SCOPUS, Curation, Current Contents Engineering Computing & Technology, Essential Science Indicators, Pdf2xml, Pdf2xml, Reference Master, Sophia
Makale Dili İngilizce
Basım Tarihi 02-2020
Cilt No 45
Sayı 7
Sayfalar 4720 / 4730
Doi Numarası 10.1016/j.ijhydene.2019.12.005
Makale Linki https://linkinghub.elsevier.com/retrieve/pii/S0360319919344659