(1. 南昌航空大學(xué) 材料科學(xué)與工程學(xué)院，南昌 330063；
2. 廣西大學(xué) 物理科學(xué)與工程技術(shù)學(xué)院，南寧 530004)
摘 要: 尖晶石型鈷鐵氧體因具有良好的電磁性質(zhì)，廣泛應(yīng)用于電子裝備、微波裝備及高密度磁存儲等領(lǐng)域。采用基于密度泛函理論(DFT)的第一性原理平面波贗勢法，結(jié)合廣義梯度近似(GGA+U)，系統(tǒng)研究不同Ni摻雜量對CoFe2O4晶體結(jié)構(gòu)、電子結(jié)構(gòu)和磁性能的影響。結(jié)果表明：Ni離子傾向于占據(jù)八面體位置且隨著Ni摻雜量的增加，晶格常數(shù)呈遞減趨勢。通過電子結(jié)構(gòu)分析表明，帶隙隨著Ni摻雜量的變化而變化，大部分都呈絕緣體，且存在強烈的3d-2p軌道雜化。磁性能依賴于Ni摻雜量，隨著Ni摻雜量的增加，晶格中的原子磁矩變化不明顯，但總磁矩呈線性遞減趨勢，這主要是因為Ni離子最外層的3d未配對電子數(shù)與Co離子最外層3d未配對電子數(shù)不同，因而對磁性能的影響較大。
關(guān)鍵字: 鈷鐵氧體；第一性原理計算；摻雜；電子結(jié)構(gòu)
（1. School of Materials science and Engineering, Nanchang Hangkong University, Nanchang 330063, China;
2. School of Physical Science and Technology, Guangxi University, Nanning 530004, China）
Abstract: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.
Key words: cobalt ferrite; first-principle calculation; dopping; electronic structure
