C.Arnoult
,
X.Devaux
,
H.Rinnert
,
M.Vergnat
材料科学技术（英文）
Ultrafine powders containing alumina nanowires are synthesized by DC arc plasma from pure aluminium metal. Nanowires grow only when reactive gases are composed of nitrogen and less than ten percent of oxygen. Nanowires have the diameters ranging from 20 to 80 nm and lengths ranging from hundreds nanometers to tens of micrometers. A first assumption of the mechanism process is proposed, in which nanowires grow starting directly from the aluminium. Photoluminescence measurements show that the powders have three emission peaks around 435, 530 and 750 nm resulting from different kinds of defects such as oxygen vacancies, aluminium interstitial ions and surface defects.
关键词:
Nanowires
,
null
,
null
,
null
Mingzai WU
,
Lianzeng YAO
,
Weili CAI
,
Guowei JIANG
,
Xiaoguang LI
,
Zhen YAO
材料科学技术（英文）
Ordered ZnO nanowire arrays embedded in anodic aluminum oxide (AAO) membranes were fabricated by electrochemical deposition of Zn(NO3)2+H3BO3 solution in a boiling bath. Scanning electron microscope (SEM) and transmission electron microscope (TEM) observation results show that the polycrystalline ZnO nanowires with diameters around 100 nm were uniformly assembled into the ordered nanochannels of the AAO. The results of the investigation into photoluminescence (PL) and electronic paramagnetic resonance (EPR) measurements reveal that the interfaces between the ZnO nanowires and the pore walls of the AAO create a lot of oxygen vacancies, which are responsible for the green light emission (peaking around 512 nm) and the huge enhancement of the PL emission.
关键词:
Nanowires
,
null
,
null
黄珊
,
王继刚
,
刘松
,
张玥晨
,
钱柳
,
梁杰
新型炭材料
以Si粉、SiO2粉和人造石墨为原料，在1480℃、4 kW、80 min的真空微波辐照条件下快速高效地合成SiC纳米线。利用SEM、TEM、XRD等对所得产物的微观结构解析表明，在未使用催化剂的条件下，基于气固( VS)机制可成功制备出β型SiC。根据坩埚中的部位不同，所得SiC呈现出不同的形貌。坩埚上层的产物呈亮绿色，较为纯净，主要为直径约150 nm的纳米棒，并含有部分微米级SiC晶粒，表面氧化迹象不明显。其余部分产物呈灰绿色，主要是直径为20~50 nm的SiC/SiO2同轴纳米线(表层的SiO2厚度约2 nm)，并夹杂有未反应完全的石墨和SiO2。利用波长为240 nm的激发光分别对SiC纳米棒和同轴纳米线的光致发光特性的测试表明，两者均可观察到峰位在390 nm左右的发射峰，此结果与所报道的β-SiC纳米材料的发光性能相比，蓝移程度更高。
关键词:
微波法
,
碳化硅
,
纳米线
,
结构表征
,
光致发光
