Effect of metal-ligand bond lengths on superexchange interactions in Jahn-Teller d4 ion systems:: Spin dimer analysis of the magnetic structure of marokite CaMn2O4
Effect of metal-ligand bond lengths on superexchange interactions in Jahn-Teller d4 ion systems:: Spin dimer analysis of the magnetic structure of marokite CaMn2O4
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DOI：
10.1021/ic0202458
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发表时间：
2002-10-21
影响因子：
4.6
通讯作者：
Jung, D
中科院分区：
文献类型：
--
作者：
Whangbo, MH;Koo, HJ;Jung, D
在marokite CaMn2O4中，由于jhn - teller畸变，每个MnO6八面体的所有6个Mn-O键都是不同的，因此每个Mn3+ (d(4))离子与其相邻的Mn3+离子有6个不同的超交换作用。在自旋二聚体分析的基础上，研究了CaMn2O4的自旋交换相互作用，找出了Mn-O-Mn超交换路径的几何参数控制其自旋交换相互作用的符号和强度。我们的工作正确地描述了从中子粉末衍射测量中观察到的CaMn2O4的磁性结构，并表明Mn-O- mn路径的反铁磁相互作用主要取决于Mn-O- mn桥的不对称性和Mn-O键长度，而不是ZMn-O-Mn键角。
In marokite CaMn2O4, all six Mn-O bonds of each MnO6 octahedron are different because of the Jahn-Teller distortion so that every Mn3+ (d(4)) ion has six different superexchange interactions with its neighboring Mn3+ ions. The spin exchange interactions of CaMn2O4 were examined on the basis of spin dimer analysis to find what geometrical parameters of the Mn-O-Mn superexchange paths control the signs and strengths of their spin exchange interactions. Our work correctly describes the magnetic structure of CaMn2O4 observed from neutron powder diffraction measurements and shows that the antiferromagnetic interactions of the Mn-O-Mn paths depend primarily on the asymmetry and the Mn-O bond length of the Mn-O-Mn bridge, but not on the ZMn-O-Mn bond angle.