超高真空中锗衬底上铁锗化合物纳米结构的外延生长  

Epitaxial Growth of Fe-Germanide Nanostructures on Reconstructed Ge Substrate

作　　者：施凯娟 邹志强[2] 刘晓勇[2] 

机构地区：[1]上海交通大学材料科学与工程,上海200240 [2]上海交通大学分析测试中心,上海200240

出　　处：《真空科学与技术学报》2017年第5期527-532,共6页Chinese Journal of Vacuum Science and Technology

基　　金：国家自然科学基金项目(61176017)

摘　　要：采用分子束外延法在250~700℃的Ge(111)衬底表面生长出铁的锗化物纳米结构,原位扫描隧道显微镜观察表明,在300℃以下,Ge(111)衬底上生长的铁锗化合物以三维岛的形式存在,高于此温度,Ge(111)衬底上将生长出短棒和纳米线形状的铁锗化合物。当温度高于550℃时,Ge(111)衬底上只有纳米线生成,且纳米线沿着<1-10>三个等价方向生长,具有三重对称性。扫描隧道谱测量表明,三维岛具有金属特性而短棒和纳米线则呈现半导体性质。此外,X射线光电子能谱测试表明,相对于三维岛,纳米线的Fe2p3/2和Fe2p1/2峰向低结合能方向发生了移动,进一步证明了从三维岛到纳米线发生了相变。The Fe-germinide nanostructureswere synthesized by reactive molecular beam epitaxial growth on Ge （ 111 ） -2 × 8 reconstructed surfaces. The impact of the substrate temperature on the Fe-Germanide nanostructures and its growth mode was in-situ investigated with scanning tunneling microscopy, scanning tunneling spectroscopy （STS） and X-ray photoelectron spectroscopy. The results show that the substrate temperature significantly affected the nanostructures, including 3-D islands, nano-wires and nano-rods. To be specific, synthesized at a temperature below 300℃ , metallic 3-D islands of Fe-germinide formed; above 300℃ , semi-conducting nano-wires and nano-rods coexisted; above 550℃, only nano-wires, with threefold symmetry and grown in 〈 1-10 〉 three equivalent directions, showed up. As shown in the STS spectra,the positions of Fe-2p3/2 and Fe-2p1/2 peaks of the nanowires were slightly lower than those of the 3-D islands,indicating a phase transition from 3-D islands to nanowires.

关 键 词：扫描隧道显微镜 X射线光电子能谱 铁锗化合物 纳米线 三维岛 

分 类 号：TN16[电子电信—物理电子学]