| Cite this article as: Lu Qing-Mei,Zhang Fei-Peng,Fang Hui,Li Hong-Fei,Liu Wei-Qiang,Zhang Dong-Tao,Yue Ming. Investigation on Electronic States as well as Magnetic Properties of the MnGa Alloy under Stress [J]. J. At. Mol. Phys.(原子与分子物理学报), 2023, 40: 016002 (in Chinese) |
| Investigation on Electronic States as well as Magnetic Properties of the MnGa Alloy under Stress |
| Hits 511 Download times 183 Received:October 29, 2021 Revised:November 22, 2021 |
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| Key Words
MnGa alloys Stress Electronic properties Magnetic properties |
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| Abstract
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| The formation, geometry, electronic as well as magnetic properties of the tetragonal MnGa alloy under 1GPa stress along a-axis are investigated by density functional theory analyzing method. The results show that the lattice constants a and b are increased, but the constant c is decreased，the angles tend to deviate from 90° and the volume is increased under stress. There is no bond between Mn and Ga, the strong bond between Mn and Mn is enhanced, whereas the strong bond between Ga and Ga disappears. Both the distance between Mn and Mn and that between Ga and Ga are decreased, but the distance between Mn and Ga is increased, and their repulsive effect is weakened. The formation enthalpy decreases from -4.85 eV to -5.4 eV, and so the alloy is easier to be formed. The bands are all lowered, the conduction band and the shallow valance band are wide with smaller effective mass, whereas the deep valance band is narrow with larger effective mass. There is no band gap for the spin down band and an indirect band gap of 0.26 eV for the spin up band. The s and p electrons form the conduction band and the high energy valance band, there is weak spin polarization. The d electrons mainly form the deep valance band, the localization and spin polarization effect are the strongest. All Ga atoms have almost the same electronic configurations. The d electrons of Ga mainly contribute the deep density of states, they do not contribute to the magnetic properties. The s and p electrons of Ga form obvious spin polarization, they form weak magnetism. The two kinds of Mn contribute mainly to the density of states near Fermi energy and they form distinctively strong spin polarization, especially for the d electrons of Mn. Under and above Fermi energy, the density of state value for the spin down electrons of Mn1 is respectively very higher and very lower than that of the Mn2. Magnetic transition in MnGa is induced under stress. |
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