Zhu Li-Fang, Liu Bang-Gui
Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China. Beijing National Laboratory for Condensed Matter Physics, Beijing 100190, People's Republic of China.
J Phys Condens Matter. 2009 Nov 4;21(44):446005. doi: 10.1088/0953-8984/21/44/446005. Epub 2009 Oct 15.
We explore how much the RKKY spin interaction can contribute to the high-temperature ferromagnetism in cubic (Ga, Mn)N diluted magnetic semiconductors. The usual coupling constant is used and effective carriers are considered independent of doped magnetic atoms, as is shown experimentally. Our Monte Carlo simulated results show that maximal Curie temperature is reached at the optimal carrier concentration for a given Mn concentration, equaling 373 K for 5% Mn and 703 K for 8% Mn. Because such a Monte Carlo method does not overestimate transition temperatures, these calculations indicate that the RKKY spin interaction alone can yield high-enough Curie temperatures in cubic (Ga, Mn)N under optimized conditions.
我们探究了RKKY自旋相互作用对立方结构（Ga，Mn）N稀磁半导体中高温铁磁性的贡献程度。采用了通常的耦合常数，并如实验所示，认为有效载流子与掺杂磁性原子无关。我们的蒙特卡罗模拟结果表明，对于给定的Mn浓度，在最佳载流子浓度下可达到最高居里温度，5% Mn时为373 K，8% Mn时为703 K。由于这种蒙特卡罗方法不会高估转变温度，这些计算表明，在优化条件下，仅RKKY自旋相互作用就能在立方结构（Ga，Mn）N中产生足够高的居里温度。
