First-principles investigations of Zn (Cd) doping effects on the electronic structure and magnetic properties of CoFe2O4
First-principles investigations of Zn (Cd) doping effects on the electronic structure and magnetic properties of CoFe2O4
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DOI：
10.1063/1.3535442
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发表时间：
2011-03
影响因子：
3.2
通讯作者：
Y. Hou;Yu-Jun Zhao;Zuolian Liu;Huangzhong Yu;X. Zhong;W. Qiu;D. Zeng;L. Wen
中科院分区：
文献类型：
--
作者：
Y. Hou;Yu-Jun Zhao;Zuolian Liu;Huangzhong Yu;X. Zhong;W. Qiu;D. Zeng;L. Wen
采用第一性原理方法对尖晶石型Co_（1-x）Zn（Cd）_xFe_2 O_4（x = 0.0，0.25，0.5，0.75和1.0）的电子结构和磁性进行了系统的研究.优化后的结构表明，随着Zn（Cd）含量的增加，当Co离子被Zn（Cd）离子完全取代时，晶格常数增加了1.47%（5.13%）。随着Zn（Cd）掺杂量的增加，Co/Fe离子的磁矩增加，总自旋磁矩从x = 0.0时的3.00 μ B增加到x = 1.0时的10.00 μB。Zn（Cd）掺杂的CoFe 2 O 4化合物中，由于t2 g和eg能级之间的晶场分裂，Co自旋下降子带中的电子分布高度局域化，并且Zn（Cd）掺杂时能带下移。同时，随着Zn（Cd）掺杂量的增加，禁带宽度减小，但x = 1时除外，且在一定掺杂量下，尖晶石结构为半金属结构。
The electronic structures and magnetic properties of spinel Co1-x Zn (Cd)xFe2O4 (x = 0.0, 0.25, 0.5, 0.75, and 1.0) have been studied systematically by the first-principles calculation. The optimized structures show that with increasing Zn (Cd) content the crystal lattice parameter increases by 1.47% (5.13%) when the Co ions are completely replaced by Zn (Cd) ions. The results also indicate that the magnetic moment of Co/Fe ion increases and the total spin magnetic moment linearly increases with the Zn (Cd) doping from 3.00 μB for x = 0.0 up to 10.00 μB for x = 1.0 per formula unit. The electronic distribution in the Co spin-down subband is highly localized for the crystal field splitting between t2g and eg levels in the Zn (Cd) doped CoFe2O4 compounds and the energy band moves downwards while doped with Zn (Cd). Meanwhile, the bandgap decreases with the increase of Zn (Cd) except where x = 1 and the spinel structure is half-metal at some degree of doping.