Huang D J, Chang C F, Jeng H-T, Guo G Y, Lin H-J, Wu W B, Ku H C, Fujimori A, Takahashi Y, Chen C T
National Synchrotron Radiation Research Center, Hsinchu 30077, Taiwan.
Phys Rev Lett. 2004 Aug 13;93(7):077204. doi: 10.1103/PhysRevLett.93.077204. Epub 2004 Aug 11.
We present measurements of the spin and orbital magnetic moments of Fe3O4 by using SQUID and magnetic circular dichroism in soft x-ray absorption. The measurements show that Fe3O4 has a noninteger spin moment, in contrast to its predicted half-metallic feature. Fe3O4 also exhibits a large unquenched orbital moment. Calculations using the local density approximation including the Hubbard U method and the configuration interaction cluster-model suggest that strong correlations and spin-orbit interaction of the 3d electrons result in the noninteger spin and large orbital moments of Fe3O4.
我们通过使用超导量子干涉仪（SQUID）和软X射线吸收中的磁圆二色性，给出了Fe3O4的自旋和轨道磁矩的测量结果。测量结果表明，与预测的半金属特性相反，Fe3O4具有非整数自旋矩。Fe3O4还表现出较大的未猝灭轨道矩。使用包括哈伯德U方法和组态相互作用簇模型的局域密度近似进行的计算表明，3d电子的强关联和自旋轨道相互作用导致了Fe3O4的非整数自旋和大轨道矩。
