功能材料
功能材料
공능재료
JOURNAL OF FUNCTIONAL MATERIALS
2012年
13期
1782-1785
,共4页
张军战%张颖%蒋明学%刘民生
張軍戰%張穎%蔣明學%劉民生
장군전%장영%장명학%류민생
碳热还原%SiC晶须%形貌结构%生长机理
碳熱還原%SiC晶鬚%形貌結構%生長機理
탄열환원%SiC정수%형모결구%생장궤리
carbothermal reduction%SiC whiskers%morphology and crystal structure%growth mechanism
分别以SiO2微粉和Si3N4为硅源,炭黑为碳源,氧化硼为催化剂,采用碳热还原法在1500℃氩气气氛下合成了SiC晶须。通过透射电镜和扫描电镜对所合成SiC晶须的形貌和晶体结构特征进行了分析。结果表明,采用两种硅源所合成的晶须均为B—SiC单晶,晶须的生长面为(111)面,生长方向为[111]方向。两种硅源所合成的晶须形貌特点存在较大差别,表明其合成SiC晶须的生长机理不同,VLS生长和螺旋位错的延伸生长可以分别用来解释以SiO2微粉为硅源和以Si3N4为硅源合成的晶须在形貌结构特征上的差别。
分彆以SiO2微粉和Si3N4為硅源,炭黑為碳源,氧化硼為催化劑,採用碳熱還原法在1500℃氬氣氣氛下閤成瞭SiC晶鬚。通過透射電鏡和掃描電鏡對所閤成SiC晶鬚的形貌和晶體結構特徵進行瞭分析。結果錶明,採用兩種硅源所閤成的晶鬚均為B—SiC單晶,晶鬚的生長麵為(111)麵,生長方嚮為[111]方嚮。兩種硅源所閤成的晶鬚形貌特點存在較大差彆,錶明其閤成SiC晶鬚的生長機理不同,VLS生長和螺鏇位錯的延伸生長可以分彆用來解釋以SiO2微粉為硅源和以Si3N4為硅源閤成的晶鬚在形貌結構特徵上的差彆。
분별이SiO2미분화Si3N4위규원,탄흑위탄원,양화붕위최화제,채용탄열환원법재1500℃아기기분하합성료SiC정수。통과투사전경화소묘전경대소합성SiC정수적형모화정체결구특정진행료분석。결과표명,채용량충규원소합성적정수균위B—SiC단정,정수적생장면위(111)면,생장방향위[111]방향。량충규원소합성적정수형모특점존재교대차별,표명기합성SiC정수적생장궤리불동,VLS생장화라선위착적연신생장가이분별용래해석이SiO2미분위규원화이Si3N4위규원합성적정수재형모결구특정상적차별。
Using microsilica and Si3N4 as silicon sources, black carbon as carbon source, B2O3 as catalyst, SiC whiskers were synthesized under argon atmosphere at 1500℃ by carbothermal reduction method. Morphology and crystal structure of SiC whiskers were characterized by transmission electron microscope and scanning elec- tron microscope. The results show that the SiC whiskers synthesized lay using two kinds of silica sources are both/3-SIC single crystals, and the growth plane is (111) along the direction of [111]. The obvious differences in morphology indicate that there are different growth mechanisms of SiC whiskers synthesized by using differ- ent silica sources. VLS growth and screw dislocation growth are suitable to explain the differences in morpholo- gy of two kinds of SiC whiskers respectively.