Open AccessStability and electronic structure of magnesium hydride and magnesium deuteride under high pressure
Author(s) -
Chayaphon Boonchot,
Prutthipong Tsuppayakornaek,
Udomsilp Pinsook,
Thiti Bovornratanaraks
Publication year - 2021
Publication title -
journal of physics. conference series
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.21
H-Index - 85
eISSN - 1742-6596
pISSN - 1742-6588
DOI - 10.1088/1742-6596/2145/1/012026
Subject(s) - superconductivity , magnesium , phonon , hydride , magnesium diboride , magnesium hydride , metal , electronic structure , high pressure , phase (matter) , materials science , electronic band structure , enthalpy , band gap , density functional theory , chemistry , condensed matter physics , thermodynamics , computational chemistry , physics , metallurgy , critical current , organic chemistry
Metal polyhydrides have attracted considerable attention because some of them become a metal under high pressure, and some undergo a phase transition into a superconductor. Some superconducting metal polyhydrides have recently been discovered with a high value of critical temperature (T c ) under pressure. In this research, we calculated the structures of MgH 2 , MgH 3 and MgD 3 under pressure between 0-300 GPa in order to determine the formation enthalpy and electronic property of their structures under high pressure by using density functional theory (DFT) based on the Quantum Espresso code. We found that the band structures reveal the metallic character of the compounds under high pressure. The energy band structures of MgH x and MgD x are exactly the same. However, their phonon dispersions are different due to the so-called isotope effect. We determined the composition stability by using the convex hull of Mg, H and the compounds. We found that MgH3 becomes thermodynamically more stable than MgH 2 at around 150 GPa. The results of phonons confirm that they are dynamically stable. This finding is served as a basis for future superconducting calculations.