Self-organization of various“phase-separated”nanostructures in a single chemical vapor deposition  

作　　者：Jinmei Wang Dongyue Xie Zhen Li Xiaohang Zhang Xing Sun Amanda L.Coughlin Thomas Ruch Qiang Chen Yaroslav Losovyj Seunghun Lee Heshan Yu Haidong Zhou Haiyan Wang Jian Wang Shixiong Zhang 

机构地区：[1]Department of Physics,Indiana University,Bloomington,Indiana,47405,USA [2]Department of Mechanical&Materials Engineering,University of Nebraska-Lincoln,Lincoln,NE,68588,USA [3]Department of Materials Science and Engineering,University of Maryland,College Park,Maryland,20742,USA [4]School of Materials Engineering,Purdue University,West Lafayette,Indiana,47907,USA [5]Department of Physics and Astronomy,University of Tennessee,Knoxville,Tennessee,37996,USA [6]Department of Chemistry,Indiana University,Bloomington,Indiana,47408,USA [7]College of Optoelectronic Engineering,Chongqing University of Posts and Telecommunications,Chongqing,400065,China [8]Department of Materials Science and NanoEngineering,Rice University,Houston,Texas,77005,USA

出　　处：《Nano Research》2020年第6期1723-1732,共10页纳米研究（英文版）

基　　金：This work was supported,in part,by the Indiana University Vice Provost for Research through the Faculty Research Support Program,National Science Foundation Research Experience for Undergraduates grant PHY-1757646,NSF-DMR-1350002;We thank the Indiana University-Bloomington Nanoscale Characterization Facility(NCF)for the use of instruments(The XPS instrument at NCF was funded through grant NSF-DMR-1126394).

摘　　要：Chemical vapor deposition(CVD)is one of the most versatile techniques for the controlled synthesis of functional nanomaterials.When multiple precursors are induced,the CVD process often gives rise to the growth of doped or alloy compounds.In this work,we demonstrate the self-assembly of a variety of‘phase-separated’functional nanostructures from a single CVD in the presence of various precursors.In specific,with silicon substrate and powder of Mn and SnTe as precursors,we achieved self-organized nanostructures including Si/SiOx core-shell nanowire heterostructures both with and without embedded manganese silicide particles,Mn11Si19 nanowires,and SnTe nanoplates.The Si/SiOx core-shell nanowires embedded with manganese silicide particles were grown along the<111>direction of the crystalline Si via an Au-catalyzed vapor-liquid-solid process,in which the Si and Mn vapors were supplied from the heated silicon substrates and Mn powder,respectively.In contrast,direct vapor-solid deposition led to particle-free<110>-oriented Si/SiOx core-shell nanowires and<100>-oriented Mn11Si19 nanowires,a promising thermoelectric material.No Sn or Te impurities were detected in these nanostructures down to the experimental limit.Topological crystalline insulator SnTe nanoplates with dominant{100}and{111}facets were found to be free of Mn(and Si)impurities,although nanoparticles and nanowires containing Mn were found in the vicinity of the nanoplates.While multiple-channel transport was observed in the SnTe nanoplates,it may not be related to the topological surface states due to surface oxidation.Finally,we carried out thermodynamic analysis and density functional theory calculations to understand the‘phase-separation’phenomenon and further discuss general approaches to grow phase-pure samples when the precursors contain residual impurities.

关 键 词：nanomaterials synthesis silicon nanowires topological crystalline insulators phase separation chemical vapor deposition 

分 类 号：TB383[一般工业技术—材料科学与工程]