论文标题
CO替代对铁磁性Heusler化合物MN3GA的影响
Effect of Co Substitution on Ferrimagnetic Heusler compound Mn3Ga
论文作者
论文摘要
CO替代对MN $ _3 $ GA的影响，使用第一原理研究的结构和磁性特性研究。如果没有CO，铁磁性Heusler化合物MN3GA处于四方相。通过CO替代，取决于CO浓度（X）Mn $ _3 $ GA时，当x \ leq 0.5（x \ geq 0.5）时，更喜欢四方（立方）相。在两个阶段中X中，非磁性都是强大的。虽然两个MN的磁矩不会随X的明显变化，但在两个相的CO磁矩表现出不同的行为，从而在总磁矩（M_ {TOT}）中产生了不同的特征。当x \ leq 0.5（在四方相中，co磁矩都很小，导致x的m_ {tot}减少。相反，当x \ geq 0.5（在立方相时，CO磁矩约为1 $μ_b$），这负责MTOT的增加。用各种X的局部密度分析电子结构。为了阐明违反直觉的小型CO力矩，研究了磁交换相互作用，而X \ leq 0.5情况下CO和MN之间的交换系数要比X \ geq 0.5 0.5一个。
Effect of Co substitution on Mn$_3$Ga is investigated using first-principles study for structural and magnetic properties. Without Co, ferrimagnetic Heusler compound Mn3Ga is in tetragonal phase. With Co substitution, depending on Co concentration (x) Mn$_3$Ga prefers tetragonal (cubic) phase when x \leq 0.5 (x \geq 0.5). Ferrimagnetism is robust regardless of x in both phases. While magnetic moments of two Mn do not vary significantly with x, Co magnetic moment in two phases exhibit different behaviors, leading to distinct features in total magnetic moment (M_{tot}). When x \leq 0.5, in tetragonal phase, Co magnetic moment is vanishingly small, resulting in a decrease of M_{tot} with x. In contrast, when x \geq 0.5, in cubic phase, Co magnetic moment is roughly 1$μ_B$, which is responsible for an increase of Mtot. Electronic structure is analyzed with partial density of states for various x. To elucidate the counterintuitively small Co moment, the magnetic exchange interaction is investigated where exchange coefficient between Co and Mn is much smaller in x \leq 0.5 case than x \geq 0.5 one.
