Growth process and magnetic properties of iron nanoparticles deposited on Si_3N_4/Si(111)-(8×8)
Growth process and magnetic properties of iron nanoparticles deposited on Si_3N_4/Si(111)-(8×8)
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Si_3N_4/Si(111)-(8×8)上铁纳米粒子的生长过程及磁性能
DOI：
10.1103/physrevb.85.174415
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
T. Nakagawa and T. Yokoyama
中科院分区：
文献类型：
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作者：
K. Eguchi;Y. Takagi;T. Nakagawa and T. Yokoyama
利用扫描隧道显微镜、X射线磁圆二色性和磁光克尔效应研究了铁在SiN/Si（111）-（）和清洁Si（111）-（）衬底上的生长过程和磁性。实验结果表明，在干净的Si（111）-（）上，1.6-单层（ML）Fe形成自旋磁矩很小的硅化铁，而在SiN/Si（111）上，1.6-ML Fe具有大得多的自旋磁矩，比体心立方Fe（2.2）的自旋磁矩有所提高。发现SiN表面有效地抑制了硅化物的形成。由于Fe和SiN之间的弱相互作用以及可能的晶格常数失配，沉积在SiN/Si（111）上的Fe以纳米颗粒形式生长，表现出超顺磁性。在7.5 ML以上，大多数纳米颗粒彼此非常接近，并成为铁磁性。
We investigated the growth process and magnetic properties of iron deposited on SiN/Si(111)-() and clean Si(111)-() substrates by scanning tunneling microscopy, x-ray magnetic circular dichroism, and the magneto-optical Kerr effect measurements. These experiments reveal that, on clean Si(111)-(), 1.6-monolayer (ML) Fe forms iron silicide with a very small spin magnetic moment of, whereas 1.6-ML Fe on SiN/Si(111) has a much larger spin magnetic moment of, which is enhanced compared with that of bcc bulk Fe (2.2). The SiNsurface is found to suppress the silicide formation effectively. Because of weak interaction between Fe and SiNand possibly the mismatch of the lattice constant, Fe deposited on SiN/Si(111) grows as nanoparticles that exhibit superparamagnetism. Above 7.5 ML, most of the nanoparticles locate very closely to each other and become ferromagnetic.