论文标题
高压下的磁崩溃$ _3 $ se $ _4 $
Magnetic collapse in Fe$_3$Se$_4$ under high pressure
论文作者
论文摘要
使用密度功能方法计算出Fe $ _3 $ SE $ _4 $的电子结构和磁性。由于金属性能，在单元中，铁原子的磁性力矩与fe $^{3+} $和Fe $^{2+} $的离子值不同，等于$ m_1 =2.071μ1μ_b$和$ m_2 = -2.042 =-2.042μ_b$，使系统ferrimagnectic ferrimagnetic。单元电池的总磁矩为$2.135μ_b$。在各向同性压缩下，总磁矩会降低非单调性，并与费米级$ n（e_f）$的状态密度的非单调依赖性相关。对于7％的压缩，磁顺序从铁磁性变为铁磁。在14％的压缩时，磁顺序消失，总磁矩变为零，使系统处于顺磁状态。该压缩对应于114 GPA的压力。由于化学键在fe $ _3 $ _3 $ se $ _4 $中，磁性排序在施加各向同性外部压力时的变化更快。铁磁性和顺磁性状态分别出现在5.0和8.0 GPa的压力下。对于所有压缩值，该系统仍处于金属状态。
Electronic structure and magnetic properties of Fe$_3$Se$_4$ are calculated using the density functional approach. Due to the metallic properties, magnetic moments of the iron atoms in two nonequivalent positions in the unit cell are different from ionic values for Fe$^{3+}$ and Fe$^{2+}$ and are equal to $M_1=2.071 μ_B$ and $M_2=-2.042 μ_B$, making the system ferrimagnetic. The total magnetic moment for the unit cell is $2.135 μ_B$. Under isotropic compression, the total magnetic moment decreases non-monotonically and correlates with the non-monotonic dependence of the density of states at the Fermi level $N(E_F)$. For 7% compression, the magnetic order changes from the ferrimagnetic to the ferromagnetic. At 14% compression, the magnetic order disappears and the total magnetic moment becomes zero, leaving the system in a paramagnetic state. This compression corresponds to the pressure of 114 GPa. The magnetic ordering changes faster upon application of an isotropic external pressure due to the sizeable anisotropy of the chemical bondings in Fe$_3$Se$_4$. The ferrimagnetic and paramagnetic states occur under pressures of 5.0 and 8.0 GPa, respectively. The system remains in the metallic state for all values of compression.
