Fakultät für Physik and Center for Computational Materials Science, Universität Wien, Sensengasse 8/12, A-1090 Wien, Austria.
J Chem Phys. 2011 Jan 21;134(3):034107. doi: 10.1063/1.3530799.
Ab initio density functional calculations including spin-orbit coupling (SOC) have been performed for Pt(n), n = 2-6 clusters. The strong SOC tends to stabilize planar structures for n = 2-5, whereas for clusters consisting of six atoms, three-dimensional structures remain preferred. SOC leads to the formation of large orbital magnetic moments and to a mixing of different spin states. Due to the spin-mixing the total magnetic moment may be larger or smaller than the spin moment in the absence of SOC. Both spin and orbital moments are found to be anisotropic. Because of the strong SOC the energy differences between coexisting magnetic isomers can be comparable to or even smaller than their magnetic anisotropy energies. In this case the lowest barrier for magnetization reversal can be determined by a magnetic isomer which is different from the ground state configuration.
我们对 Pt(n)（n=2-6）团簇进行了包括自旋轨道耦合（SOC）在内的从头算密度泛函理论计算。强 SOC 倾向于稳定 n=2-5 的平面结构，而对于由六个原子组成的团簇，三维结构仍然是首选。SOC 导致大的轨道磁矩的形成，并导致不同自旋态的混合。由于自旋混合，总磁矩可能大于或小于不存在 SOC 时的自旋矩。发现自旋和轨道矩都是各向异性的。由于强 SOC，共存磁性异构体之间的能量差异可以与甚至小于它们的磁各向异性能量相当。在这种情况下，磁化反转的最低势垒可以由不同于基态构型的磁性异构体来确定。
