第一性原理计算和Monte Carlo算法耦合对共掺杂稀磁半导体磁学性质的研究

First-principles and Monte Carlo combinational study on magnetic properties of co-doped DMSs

将第一性原理计算和Monte Carlo算法耦合,对共掺杂稀磁半导体进行模拟,预测其磁学性质,并与同种过渡金属原子单掺杂稀磁半导体相比较进行分析.首先用第一性原理计算掺杂原子间的磁相互作用强度,作为后面Monte Carlo模拟的输入参数;然后利用Monte Carlo方法结合海森堡自旋模型和磁相互作用强度来模拟体系热力学磁化强度和磁化率,由此得到居里温度;用同样的方法模拟掺杂磁性体系的磁滞回线.计算结果显示,对应于掺Co、Al-Co、Fe、Al-Fe的ZnO基稀磁半导体的居里温度分别为346 K、450 K、743 K、467 K,与实验值很吻合;模拟这四种掺杂情况得到的磁滞回线也很符合理论分析和实验结果,且呈现和居里温度相同的变化规律.

The magnetic properties of co-doped DMSs are predicted using first-principles calculations in combination with Monte Carlo （MC） simulation, which will be compared with DMSs doped with the same transition metal. Through the magnetic coupling strengths obtained from first-principles, and then combining with Heisenberg spin model, the Monte Carlo simulates magnetizations and magnetic susceptibilities of DMSs to obtain the Curie temperatures, and also the magnetic hysteresis loops. The results reveal that the Curie temperatures of DMSs doped with Co, Al-Co, Fe and Al-Fe are 346 K, 450 K, 743 K and 467 K respectively, which is generally consistent with some experimental facts. What＇s more, the hysteresis loops are also in accord with theoretical and experimental results, and follow the same rules of the Curie temperatures.