Collinear Superexchange Interaction between Inequivalent Ions:V2+andNi2+in MgO
Collinear Superexchange Interaction between Inequivalent Ions:V2+andNi2+in MgO
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MgO中不等价离子V2和Ni2之间的共线超交换相互作用
DOI：
10.1103/physrev.164.636
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发表时间：
1967
期刊：
影响因子：
--
通讯作者：
N. L. Huang
中科院分区：
文献类型：
--
作者：
N. L. Huang
采用Dirac-VanVleck-Serber组态相互作用方法，研究了V2+和Ni 2+离子间的共线超交换相互作用.用这种方法导出的交换积分的主要项与安德森势交换机制的结果是等价的。超交换作用的主要贡献来自配体p σ轨道的自旋极化，通过与Ni 2+离子的共价混合，以及V2+离子的自旋与极化p σ轨道之间的直接交换.的相互作用的强度计算为7.3 K（铁磁性）的V 2+和Ni 2+离子在MgO中，预计这是一个值太小的约2倍。利用KNiF 3和V2+：KMgF 3中未成对自旋密度的测量值，对V2+和Ni 2+离子在KMgF 3中的交换积分进行了半经验估计.在这种情况下，共线超交换的强度预计约为15 K。
The Dirac-Van Vleck-Serber method of configuration interaction is applied to formulate the collinear superexchange interaction between V 2+ and Ni 2+ ions. The major terms of the exchange integral derived by using this method are found to be equivalent to the result of Anderson's mechanism of potential exchange. The dominant contribution to the superexchange interaction is found to arise from the spin polarization of the ligand p σ orbitals via covalent mixing with Ni 2+ ions, in cooperation with the direct exchange between the spins of V 2+ ions and the polarized p σ orbitals. The strength of the interaction is computed to be 7.3 K (ferromagnetic) for V 2+ and Ni 2+ ions in MgO, a value which is expected to be too small by a factor of about 2. A semiempirical estimate for the exchange integral is performed for V 2+ and Ni 2+ ions in KMg F 3 by using the measured values for the unpaired spin densities in KNi F 3 and V 2+: KMg F 3. The strength of collinear superexchange is expected to be roughly 15 K for this case.