Modifications of magnetic properties of Pt/Co/Pt thin layers by focused gallium ion beam irradiation
Modifications of magnetic properties of Pt/Co/Pt thin layers by focused gallium ion beam irradiation
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DOI：
10.1063/1.1427144
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发表时间：
2002-03-01
影响因子：
3.2
通讯作者：
Bernas, H
中科院分区：
文献类型：
--
作者：
Vieu, C;Gierak, J;Bernas, H
我们展示了如何在20-100 keV范围内的低能量密度的Ga+离子均匀照射下，可以修改和甚至控制的Pt/Co薄膜结构的磁性能。对Pt/Co（1.4nm）/Pt（111）超薄膜结构进行了系统的磁光研究。当离子注量低于D=10（14）Ga+/cm（2）时，矫顽场随着注量的增加而稳定地减小。在D=（5-10）× 10（14）Ga+ ions/cm（2）范围内的大注量下，Co层的磁化强度迅速下降，并且对于D> 2 × 10（15）Ga+ ions/cm（2），膜最终在室温下变为顺磁性。我们表明，这些磁性变化与离子诱导的碰撞混合的Co/Pt界面的效果，导致形成稳定的Co-Pt合金与不同的组合物的界面。一个简单的模型推导出有关的离子束诱导的混合的磁性能的变化。目前的工作使我们能够获得一个定量的了解以前的实验，使用一个集中的Ga+离子束图案类似的样品在一个子100纳米尺度的磁性能。(C)2002年美国物理学会。
We show how the magnetic properties of the Pt/Co ultrathin film structure can be modified and even controlled under uniform irradiation by Ga+ ions at low fluence in the 20-100 keV range. A systematic magneto-optical study is presented for the Pt/Co(1.4 nm)/Pt(111) ultrathin-film structure. At ion fluences below D=10(14) Ga+/cm(2), the coercive field is steadily reduced when increasing the fluence. At large fluences, in the range D=(5-10)x10(14) Ga+ ions/cm(2), the magnetization of the Co layer drops rapidly and the film finally becomes paramagnetic at room temperature for D>2x10(15) Ga+ ions/cm(2). We demonstrate that these magnetic changes are related to the effect of ion-induced collisional intermixing of the Co/Pt interfaces, leading to the formation of stable Co-Pt alloys with varying composition across the interfaces. A simple model is derived to relate the ion beam-induced mixing to the changes in magnetic properties. The present work allows us to gain a quantitative understanding of previous experiments using a focused Ga+ ion beam to pattern magnetic properties of similar samples at a sub-100 nm scale. (C) 2002 American Institute of Physics.