合金团簇(FeCr)n中的非共线磁序和自旋轨道耦合效应

利用密度泛函理论对合金团簇(FeCr)_n (n≤6)的几何结构、稳定性和磁性进行了系统的研究. 研究结果表明, 对n≤3的合金团簇, 其基态具有共线的反铁磁序; 而对于n≥4 的合金团簇, 其基态具有非共线磁序, 因此在n=4时体系发生了共线磁序向非共线磁序的“相变”. 此外, 虽然3d过渡金属原子中电子的自旋轨道耦合效应比较弱, 但计算结果表明对于某些小尺寸的合金团簇其轨道磁矩不能忽略. 对非共线磁性团簇的成键性质以及产生磁序“相变”的物理起源进行了详细讨论. 关键词： n合金团簇')" href="#">(FeCr)_n合金团簇 密度泛函理论 非共线磁序 自旋轨道耦合效应

Noncollinear magnetic order and spin-orbit coupling effect in (FeCr)n alloying clusters

Using density functional theory, the structures, stabilities and magnetic properties of (FeCr)_n (n≤ 6) alloying clusters are systematically investigated. For smaller clusters with n≤3, the results show that the ground-state system possesses collinear antiferromagnetic order. For n≥4 cases, however, the ground-state cluster has noncollinear magnetic order. Therefore, there is a collinear-to-noncollinear magnetic transition at n=4 in (FeCr)_n systems. In addition, although the spin-orbit coupling effect of 3d transition metal atom is often weak, the results indicate that the orbital magnetic moments of some certain clusters are significant and important. Finally, the chemical bond of noncollinear magnetic clusters and the physical origin of the magnetic transition are analyzed.
Keywords： n alloying clusters')" href="#">(FeCr)_n alloying clusters density functional theory noncollinear magnetic order spin-orbit coupling effect