Microstructure evolution and growth mechanism of core-shell silicon-based nanowires by thermal evaporation of SiO  

作　　者：Bing LIU Jia SUN Lei ZHOU Pei ZHANG Chenxin YAN Qiangang FU 

机构地区：[1]State Key Laboratory of Solidification Processing,Shaanxi Key Laboratory of Fiber Reinforced Light Composite Materials,Northwestern Polytechnical University,Xi’an 710072,China

出　　处：《Journal of Advanced Ceramics》2022年第9期1417-1430,共14页先进陶瓷（英文）

基　　金：This work was supported by the National Natural Science Foundation of China(Nos.52061135102,52101098);Innovation Talent Promotion Plan of Shaanxi Province for Science and Technology Innovation Team(No.2020TD-003);Young Talents for Science and Technology Association supported by Shaanxi Province(No.20200406);the Fund of Key Laboratory of National Defense Science and Technology in Northwestern Polytechnical University(No.JCKYS2020607003);Innovation and Entrepreneurship Training Program for College Students(No.202110699088).

摘　　要：Core-shell structured SiC@SiO_(2)nanowires and Si@SiO_(2)nanowires were prepared on the surface of carbon/carbon(C/C)composites by a thermal evaporation method using SiO powders as the silicon source and Ni(NO3)2 as the catalyst.The average diameters of SiC@SiO_(2)nanowires and Si@SiO_(2)nanowires are about 145 nm,and the core-shell diameter ratios are about 0.41 and 0.53,respectively.The SiO_(2)shells of such two nanowires resulted from the reaction between SiO and CO and the reaction of SiO itself,respectively,based on the model analysis.The growth of these two nanowires conformed to the vapor-liquid-solid(VLS)mode.In this mode,CO played an important role in the growth of nanowires.There existed a critical partial pressure of CO(pC)determining the microstructure evolution of nanowires into whether SiC@SiO_(2)or Si@SiO_(2).The value of pC was calculated to be 4.01×10^(-15) Pa from the thermodynamic computation.Once the CO partial pressure in the system was greater than the pC,SiO tended to react with CO,causing the formation of SiC@SiO_(2)nanowires.However,the decomposition of SiO played a predominant role and the products mainly consisted of Si@SiO_(2)nanowires.This work may be helpful for the regulation of the growth process and the understanding of the growth mechanism of silicon-based nanowires.

关 键 词：SiC@SiO_(2)nanowires Si@SiO_(2)nanowires carbon/carbon(C/C)composites growth mechanism thermal evaporation 

分 类 号：TB383[一般工业技术—材料科学与工程]