First-principles calculations of structural, electronic, magnetic and elastic properties of Mo2FeB2 under high pressure

The structural and electronic density of states, magnetic, and elastic properties of Mo2FeB2 under high pressure have been investigated with first principles calculations. Furthermore, the thermal dynamic properties of Mo2FeB2 were also studied with the quasiharmonic Debye model. The volume of Mo2FeB2 decreases with the increasing pressure. Using the analysis of the density of the states, atom population and Mulliken overlap population, it is observed that as the pressure increases, the B-B bonds are strengthened, and the B-Mo covalency decreases. Moreover, for all pressures, Mo2FeB2 is detected in the antiferromagnetic phase and the magnetic moments decrease with the increasing pressure. The calculated bulk modulus, shear modulus, Young’s modulus, Poisson’s ratio and universal anisotropy index all increase with the increasing pressure. From thermal expansion coefficient analysis, it is found that Mo2FeB2 shows good volume invariance under high pressure and temperature. The examination ...

本研究采用第一性原理计算（first principles calculations）方法，探究了高压下Mo₂FeB₂的结构、电子态密度、磁学与弹性性质。此外，本研究还通过准谐德拜模型（quasiharmonic Debye model）对Mo₂FeB₂的热力学性质开展了分析。结果表明，Mo₂FeB₂的晶胞体积随压力升高而减小。通过态密度、原子布居及马利肯（Mulliken）重叠布居分析发现，随着压力升高，B-B键得到增强，而B-Mo键的共价性则有所减弱。此外，在所有研究压力范围内，Mo₂FeB₂均呈现反铁磁相，且其磁矩随压力升高而降低。计算得到的体积模量、剪切模量、杨氏模量、泊松比以及通用各向异性指数均随压力升高而增大。通过热膨胀系数分析可知，Mo₂FeB₂在高压高温条件下展现出优异的体积稳定性。本研究的相关考察……