Calculation of exchange integrals and electronic structure of manganese ferrite (MnFe2O4)
Calculation of exchange integrals and electronic structure of manganese ferrite (MnFe2O4)
复制标题
锰铁氧体（MnFe2O4）交换积分和电子结构的计算
DOI：
10.1063/1.1558200
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发表时间：
2003
影响因子：
3.2
通讯作者：
C. Vittoria
中科院分区：
文献类型：
--
作者：
X. Zuo;C. Vittoria
用密度泛函理论方法计算了锰铁氧体（MnFe2O4）的正尖晶石结构和反尖晶石结构的交换积分。泛函被选择为具有可变权重（w）的Becke交换和Fock交换的混合。将不同磁基态的总能量代入Heisenberg模型，计算了最近邻A、B位间的交换积分JAB和最近邻B位间的交换积分JBB. JAB的计算值与中子衍射和核磁共振测量的实验值符合较好。此外，参数U（库仑排斥能）和Eg（带隙）是从相对于w绘制的态密度中提取的。我们计算的带隙表明，MnFe_2O_4是一个复杂的绝缘体，在以前的本地自旋密度近似和广义梯度近似计算预测它是金属。
The exchange integrals of manganese ferrite (MnFe2O4) are calculated with the density functional theory method for both normal and inverse spinel structures. The functional is chosen to be a mixture of Becke exchange and Fock exchange with variable weight (w). The exchange integrals JAB (the exchange integral between the nearest neighbor A and B sites) and JBB (the exchange integral between nearest neighbor B sites) are calculated by substituting the total energies of different magnetic ground states into the Heisenberg model. The calculated value of JAB is in agreement with experimental values measured by neutron diffraction and nuclear magnetic resonance. Also, the parameters U (Coulomb repulsion energy) and Eg (band gap) are extracted from density of states plotted versus w. Our calculated band gap shows that MnFe2O4 is a complex insulator in contrast to previous local spin density approximation and generalized gradient approximation calculations which predicted it to be metallic.