Three-Dimensional Normal Stress for Controlling Electronic Structure and Magnetic Property of Fe 2 Ge

A system study of the three-dimensional normal stress for regulating electronic structure and magnetic property of Fe 2 Ge is studied. The density states of Fe more than 92% contribution come from Fe 3d, the density states of Ge mainly contributed from Ge 4p and Ge 4s, and the Fe 3d spin induces the Ge 4p electron transfer. The inductive effect increases germanium electron energy, weakens the Fe spin density of states, opposes the stability of the ferromagnetic state. The magnetic moment varies from 5 to 3 μB with the stress charges from -30 to 30 GPa. The charge of Fe is negative whereas the Ge atom is positively charged, the Fe atom loses charge, the charge transfers to the Ge atom. The unevenly distributed charge forms the new occupy state and spin polarization state in the Fe 2 Ge electron structure system. The Fe is the electron donor, the total electron is transferred to Ge, but the total numbers of gain electron and total numbers of lost electron are not equal, so the Fe 2 Ge electron system may have hybridization between the Fe 3d state and Ge 4p state. The magnetic of Fe 2 Ge mainly comes from the unoccupied Fe 3d orbital, the Fe 3d is positive spin-polarization state and the spin-polarization strength is decreased, the Ge 4p is negative spin-polarization state and the spin-polarization strength are increased. Moreover, electrons-spin polarization is relevant to the structure parameters of the Fe 2 Ge system, and controls spin-polarized electronic behavior by means of adjusting ferromagnetic.