Co和Mn共掺杂ZnO铁磁性的第一性原理

基于密度泛函理论(DFT)的总体能量平面波超软赝势方法,结合广义梯度近似(GGA),对Co单独掺杂ZnO和(Co,Mn)共掺杂ZnO的32原子超原胞体系进行了几何结构优化,计算了纤锌矿结构ZnO、Co-ZnO及(Co,Mn)共掺杂ZnO的能带结构、电子态密度,并对此进行了详细的分析。计算结果表明,ZnO中单独掺杂Co元素显示出铁磁性行为,Mn的引入减弱了Co-ZnO的铁磁性。

First-principle Research on Ferromagnetism of (Co,Mn)-codoped ZnO

Spintronics is a multidisciplinary field whose central theme is the active manipulation of spin degrees of freedom in electron devices.Compared with conventional semiconductor devices,due to adding the spin degree of freedom to conventional charge-based electronic devices has the potential merits of nonvolatility,increased data processing speed,reduced electric power consumption,and added integration densities.Seeking right magnetic materials is also very important.ZnO has been recognized as a promising material for optoelectronic devices,such as ultraviolet light-emitting diodes,laser diodes,and photodetectors,owing to its wide band gap and large exciton binding energy at room temperature.Diluted magnetic semiconductors are attracting considerable attention because they are anticipated to be used in the spintronic devices.For the realization of spintronic devices,the ferromagnetic semiconductors with Curie temperature above room temperature are highly expected.At present oxide-diluted magnetic semiconductors have being a focus especially based on ZnO material.First-principle's study has already broadly been applied to the material calculation.So far,much of work has concentrated on Co-or Mn-doped ZnO and characterization of their structural,magnetic,and optical properties.However,little attention was paid to(Mn,Co)-codoped ZnO system.In this paper,the geometrical structure of pure ZnO,Co doped and(Co,Mn)-codoped 32-atom supercell of ZnO was optimized by using the ultra-soft pseudopotential method of total-energy plane wave based on the density functional theory(DFT).Density of states and band structure were calculated and discussed in detail.The results revealed that Co doped ZnO and(Co,Mn)-codoped ZnO showed ferromagnetism,however,ferromagnetism of(Co,Mn)-codoped ZnO was weaken because of Mn doping.These results will provide very good references for the experiment studies.