Islam M Fhokrul, Khanna Shiv N
Department of Physics, Virginia Commonwealth University, Richmond, VA 23284-2000, USA.
J Phys Condens Matter. 2014 Mar 26;26(12):125303. doi: 10.1088/0953-8984/26/12/125303. Epub 2014 Mar 6.
We show that the magnetic anisotropy energy (MAE) in cobalt clusters can be significantly enhanced by doping them with group IV elements. Our first-principles electronic structure calculations show that Co4C2 and Co12C4 clusters have MAEs of 25 K and 61 K, respectively. The large MAE is due to controlled mixing between Co d- and C p-states and can be further tuned by replacing C by Si. Larger assemblies of such primitive units are shown to be stable with MAEs exceeding 100 K in units as small as 1.2 nm, in agreement with the recent observation of large coercivity. These results may pave the way for the use of nano-clusters in high density magnetic memory devices for spintronics applications.
我们表明，通过用IV族元素对钴团簇进行掺杂，可以显著提高其磁各向异性能量（MAE）。我们的第一性原理电子结构计算表明，Co4C2和Co12C4团簇的MAE分别为25 K和61 K。较大的MAE归因于Co d态和C p态之间的可控混合，并且可以通过用Si替代C来进一步调节。这种原始单元的更大组装体在小至1.2 nm的单元中显示出MAE超过100 K的稳定性，这与最近观察到的大矫顽力一致。这些结果可能为在自旋电子学应用的高密度磁存储器件中使用纳米团簇铺平道路。
