摘要
尖晶石型钴铁氧体因具有良好的电磁性质,广泛应用于电子装备、微波装备及高密度磁存储等领域。采用基于密度泛函理论(DFT)的第一性原理平面波赝势法,结合广义梯度近似(GGA+U),系统研究不同Ni掺杂量对CoFe_2O_4晶体结构、电子结构和磁性能的影响。结果表明:Ni离子倾向于占据八面体位置且随着Ni掺杂量的增加,晶格常数呈递减趋势。通过电子结构分析表明,带隙随着Ni掺杂量的变化而变化,大部分都呈绝缘体,且存在强烈的3d-2p轨道杂化。磁性能依赖于Ni掺杂量,随着Ni掺杂量的增加,晶格中的原子磁矩变化不明显,但总磁矩呈线性递减趋势,这主要是因为Ni离子最外层的3d未配对电子数与Co离子最外层3d未配对电子数不同,因而对磁性能的影响较大。
Spinel ferrites, such as CoFe2O4, can be applied in varied fields such as electronic equipment, microwave equipment and high density magnetic storage due to their good electromagnetic properties. The crystal structure, electronic structure and magnetic properties of Ni doped CoFe2O4 were investigated within the density functional theory in the generalized gradient approximation with Hubbard U correction （GGA＋U）. The results show that Ni ions tend to occupy the octahedral site and with the increase of Ni doping content, the lattice constant decreases. The electronic structure analysis shows that the band gap changes with the change of Ni doping content, and generally it is an insulator and there is a strong 3d-2p orbital hybridization. Magnetic properties depend on the Ni doping content, and with the increase of the Ni doping content, the lattice atomic magnetic moments of change is not obvious, but the total magnetic moment shows linear decreasing trend. It is mainly attributed to the different numbers of the unpaired electrons between Ni-3d orbitals and Co-3d orbitals, thus affects the magnetic properties obviously.
作者
侯世界
侯育花
黄有林
欧阳义芳
HOU Shi-jie HOU Yu-hua HUANG You-lin OUYANG Yi-fang(School of Materials science and Engineering, Nanchang Hangkong University, Nanchang 330063, China School of Physical Science and Technology, Guangxi University, Nanning 530004, China)
出处
《中国有色金属学报》
EI
CAS
CSCD
北大核心
2017年第7期1426-1432,共7页
The Chinese Journal of Nonferrous Metals
基金
国家自然科学基金资助项目(11304146
51401103)
江西省自然科学基金资助项目(20151BAB212005
20151BAB216003)
航空科学基金资助项目(2014ZF56017)~~
关键词
钴铁氧体
第一性原理计算
掺杂
电子结构
cobalt ferrite
first-principle calculation
dopping
electronic structure
