Shen Chin-Li, Yang Shu-Meng, Lu Kuo-Chang
Department of Materials Science and Engineering, National Cheng Kung University, Tainan 701, Taiwan.
Center for Micro/Nano Science and Technology, National Cheng Kung University, Tainan 701, Taiwan.
Nanomaterials (Basel). 2020 Sep 19;10(9):1880. doi: 10.3390/nano10091880.
In this work, we report a novel and efficient silicidation method to synthesize higher manganese silicide (HMS) nanowires with interesting characterization and physical properties. High density silicon nanowire arrays fabricated by chemical etching reacted with MnCl precursor through a unique double tube chemical vapor deposition (CVD) system, where we could enhance the vapor pressure of the precursor and provide stable Mn vapor with a sealing effect. It is crucial that the method enables the efficient formation of high quality higher manganese silicide nanowires without a change in morphology and aspect ratio during the process. X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were utilized to characterize the HMS nanowires. High-resolution TEM studies confirm that the HMS nanowires were single crystalline MnSi nanowires of Nowotny Chimney Ladder crystal structures. Magnetic property measurements show that the MnSi nanowire arrays were ferromagnetic at room temperature with a Curie temperature of over 300 K, highly depending on the relationship between the direction of the applied electric field and the axial direction of the standing nanowire arrays. Field emission measurements indicate that the 20 μm long nanowires possessed a field enhancement factor of 3307. The excellent physical properties of the HMS nanowires (NWs) make them attractive choices for applications in spintronic devices and field emitters.
在本工作中，我们报道了一种新颖且高效的硅化方法，用于合成具有有趣特性和物理性质的高锰硅化物（HMS）纳米线。通过化学蚀刻制备的高密度硅纳米线阵列，通过独特的双管化学气相沉积（CVD）系统与MnCl前驱体反应，在该系统中我们可以提高前驱体的蒸气压，并通过密封效应提供稳定的Mn蒸气。至关重要的是，该方法能够高效形成高质量的高锰硅化物纳米线，且在过程中不会改变其形态和纵横比。利用X射线衍射（XRD）、扫描电子显微镜（SEM）和透射电子显微镜（TEM）对HMS纳米线进行表征。高分辨率TEM研究证实，HMS纳米线是具有Nowotny烟囱梯状晶体结构的单晶MnSi纳米线。磁性测量表明，MnSi纳米线阵列在室温下具有铁磁性，居里温度超过300 K，这高度依赖于外加电场方向与直立纳米线阵列轴向之间的关系。场发射测量表明，20μm长的纳米线具有3307的场增强因子。HMS纳米线（NWs）优异的物理性质使其成为自旋电子器件和场发射体应用的有吸引力的选择。
