Magnetic characterization of cobalt nanowires and square nanorings fabricated by focused electron beam induced deposition
Magnetic characterization of cobalt nanowires and square nanorings fabricated by focused electron beam induced deposition
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聚焦电子束诱导沉积制备的钴纳米线和方形纳米环的磁性表征
DOI：
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发表时间：
2018
影响因子：
3.1
通讯作者：
S. Frabboni
中科院分区：
文献类型：
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作者：
F. Venturi;G. Gazzadi;A. Tavabi;A. Rota;R. Dunin‐Borkowski;S. Frabboni
用离轴电子全息术(EH)、洛伦茨透射电子显微镜(L)和磁力显微镜(MFM)研究了聚焦式电子束诱导沉积(FEBID)制备的纳米线(NWS)和方形纳米环(NWS)的磁性。EH结果表明，用5和15keV的束流能量沉积的NWS具有磁偶极子的特性，在较低能量下沉积的NWS具有较大的磁矩。利用L电子显微镜对原子核和纳米环中的磁畴壁及其运动随外加磁场的变化进行了成像。发现原子核具有几乎正方形的磁滞回线，矫顽力约为10mT。纳米环呈现出两种不同的磁化状态：在较低的面内磁场(0.02T)下，用L电子显微镜观察到了马蹄状的磁化状态；而在较高的面内磁场(0.3T)下，用L电子显微镜和磁力显微镜观察到了剩磁时的洋葱状态。我们的结果证实了FEBID适用于磁性结构的纳米制造，并证明了透射电子显微镜技术在研究和操纵纳米结构中的磁畴壁方面的多功能性。
The magnetic properties of nanowires (NWs) and square nanorings, which were deposited by focused electron beam induced deposition (FEBID) of a Co carbonyl precursor, are studied using off-axis electron holography (EH), Lorentz transmission electron microscopy (L-TEM) and magnetic force microscopy (MFM). EH shows that NWs deposited using beam energies of 5 and 15 keV have the characteristics of magnetic dipoles, with larger magnetic moments observed for NWs deposited at lower energy. L-TEM is used to image magnetic domain walls in NWs and nanorings and their motion as a function of applied magnetic field. The NWs are found to have almost square hysteresis loops, with coercivities of ca. 10 mT. The nanorings show two different magnetization states: for low values of the applied in-plane field (0.02 T) a horseshoe state is observed using L-TEM, while for higher values of the applied in-plane field (0.3 T) an onion state is observed at remanence using L-TEM and MFM. Our results confirm the suitability of FEBID for nanofabrication of magnetic structures and demonstrate the versatility of TEM techniques for the study and manipulation of magnetic domain walls in nanostructures.