Mallik Srijani, Mohd Amir Syed, Koutsioubas Alexandros, Mattauch Stefan, Satpati Biswarup, Brückel Thomas, Bedanta Subhankar
Laboratory for Nanomagnetism and Magnetic Materials (LNMM), School of Physical Sciences, National Institute of Science Education and Research (NISER), HBNI, Jatni-752050, India.
Nanotechnology. 2019 Oct 25;30(43):435705. doi: 10.1088/1361-6528/ab3554. Epub 2019 Jul 25.
In ferromagnetic (FM) metal/organic semiconductor (OSC) heterostructures charge transfer can occur which leads to induction of magnetism in the non-magnetic OSC. This phenomenon has been described by the change in the density of states in the OSC which leads to a finite magnetic moment at the OSC interface and it is called the 'spinterface'. One of the main motivations in this field of organic spintronics is how to control the magnetic moment in the spinterface. In this regard, there are several open questions such as (i) which combination of FM and OSC can lead to more moment at the spinterface? (ii) Is the thickness of OSC also important? (iii) How does the spinterface moment vary with the FM thickness? (iv) Does the crystalline quality of the FM matter? (v) What is the effect of spinterface on magnetization reversal, domain structure and anisotropy? In this context, we have tried to answer the last four issues in this paper by studying Fe/C bilayers of variable Fe thickness deposited on Si substrates. We find that both the induced moment and thickness of the spinterface vary proportionally with the Fe thickness. Such behavior is explained in terms of the growth quality of the Fe layer on the native oxide of the Si (100) substrate. The magnetization reversal, domain structure and anisotropy of these bilayer samples were studied and compared with their respective reference samples without the C layer. It is observed that the formation of spinterface leads to a reduction in uniaxial anisotropy in Fe/C on Si (100) in comparison to their reference samples.
在铁磁（FM）金属/有机半导体（OSC）异质结构中，会发生电荷转移，这会导致在非磁性OSC中感应出磁性。这种现象已通过OSC中态密度的变化来描述，该变化会导致OSC界面处出现有限的磁矩，这被称为“自旋界面”。有机自旋电子学领域的主要动机之一是如何控制自旋界面中的磁矩。在这方面，存在几个未解决的问题，例如：（i）FM和OSC的哪种组合能在自旋界面处产生更多磁矩？（ii）OSC的厚度是否也很重要？（iii）自旋界面磁矩如何随FM厚度变化？（iv）FM的晶体质量重要吗？（v）自旋界面对磁化反转、畴结构和各向异性有什么影响？在此背景下，我们试图通过研究沉积在Si衬底上具有可变Fe厚度的Fe/C双层来回答本文中的最后四个问题。我们发现，诱导磁矩和自旋界面的厚度都与Fe厚度成比例变化。这种行为可以根据Si（100）衬底原生氧化物上Fe层的生长质量来解释。研究了这些双层样品的磁化反转、畴结构和各向异性，并与没有C层的各自参考样品进行了比较。观察到，与参考样品相比，自旋界面的形成导致Si（100）上Fe/C中的单轴各向异性降低。
