卢铁城
,
林理彬
,
朱居木
无机材料学报
采用焰熔法生长金红石单晶体时，有时发现在晶体中部生长有透明、半透明间杂的包裹体，且包裹体中有平行条纹．利用ＳＥＭ和ＸＲＤ对其（１１０）面分析研究发现，包裹体是由基本为（１１０）面取向的小晶体构成的多晶体，有的小晶体受到张应力作用，有的受到压应力作用；包裹体（１１０）面中的平行条纹为晶体的层错线或晶界，取向为［００１］，它形成于热应力造成的沿（１１０）面的解理．
关键词:
金红石TiO2单晶体
,
inclusion
,
SEM
,
XRD
华丽
,
郭兴蓬
,
杨家宽
中国腐蚀与防护学报
用动电位扫描结合EDAX、XRD和SEM研究无铅焊料Sn-0.7Cu在覆Cu FR-4基板上于3.5 mass%NaCl溶液中电化学腐蚀行为及枝晶生长过程。结果显示，Sn-0.7Cu钎料腐蚀主要以共晶组织中Sn腐蚀为主；且随着电场强度增大，腐蚀电流密度增大，低电场为均匀腐蚀，高电场时有不均匀腐蚀发生。钎料枝晶生长引起“桥连”短路问题严重影响电子产品可靠性，EDAX分析表明，枝晶上Cu离子含量大于Sn离子，说明Cu离子的电化学迁移能力和还原沉积能力大于Sn。枝晶生长是螺旋式从内到外沿四个方向最快伸展的生长方式，晶粒形成存在一定取向，主要为(411)和(220)；电场强度越大，枝晶生长速率越快，桥连时间愈短；当阴、阳间距为3 mm时，两极桥连时间分别为 12.5 h（8 V），20.4 h（5 V），28.5 h（3 V），39.6 h（1 V）。XRD结果显示其腐蚀产物主要为：SnO2，SnCl4；枝晶组成主要为：Sn，SnO2， SnCl4，Cu，CuCl2。
关键词:
Sn-Cu钎料
,
corrosion behavior
,
dendrite growth
,
potentiodynamic polarization
,
SEM
,
EDAX
,
XRD
Jong Rok Ahn
材料科学技术（英文）
Four oxide nanoparticles, such as yttrium oxide, lanthanum oxide, cerium oxide and zirconium oxide were coated on rhenium filaments by an electrophoretic deposition method. The oxide coatings were examined by scanning electron microscopy, and electron emission characteristics of the oxide-coated rhenium were studied to find alternative oxide materials for replacing the hazardous thorium oxide. Among four oxides tested in this work, yttrium oxide and lanthanum oxide coated rhenium showed enhanced electron emission compared with an uncoated rhenium. However, lanthanum oxide coating evaporated too quickly in a vacuum chamber, and hence yttrium oxide was found to be the only alternative material for use in a routine mass spectrometry. An optimum coating thickness of the yttrium oxide and lanthanum oxide was around 20 μm.
关键词:
Electrophoretic deposition
,
Oxide nanoparticles
,
SEM
,
Electron emission
Liyun ZHENG
金属学报(英文版)
The corrosion behavior of zinc and its alloy under thin electrolyte layers (TEL) in 0.1M NaCl solution was investigated by cathodic polarization curves and EIS. There was only one phase in pure zinc while zinc alloy consisted of eutectic phase and primary phase. Corrosion rate of zinc alloy was faster than that of pure zinc due to the effect of the micro-galvanic couples between the primary phase and the eutectic phase. The results indicated that corrosion rate of zinc alloy was greatly enhanced under TEL than that in bulk solution. Pure zinc exhibited minimum corrosion resistance as TEL decreased to 198 μm. Zinc and its alloy exhibited localized corrosion under TEL while it was more uniform in bulk solution. There were two capacitive loops in high frequency (HF) and middle frequency (MF) respectively, with finite length diffusion in low frequency (LF) presented in EIS. For pure zinc under TEL below 300 μm an additional inductive loop presented in MF-LF. The corrosion products and morphology were respectively examined by X-ray diffraction (XRD), FTIR (Fourier Transform Infra Red) and SEM-EDS. FTIR micro spectroscopy results indicated that the component of the corrosion products was similar at different section of the specimen surface but different in content.
关键词:
Thin electrolyte layers
,
EIS
,
Cathodic polarization
,
FTIR micro spectroscopy
,
SEM
曹章轶
,
孙卓
,
郭平生
,
陈奕卫
无机材料学报
采用低压化学气相沉?积(LPCVD)在镍片上制备了厚度在400～1000μm范围的碳纳米管(CNTs)薄膜, 研究了碳源(乙炔)流量对碳纳米管薄膜形貌
和结构的影响. 随乙炔流量的增加, 碳纳米管薄膜厚度和产量增大. 电子显微镜和拉曼光谱研究结果表?明, 在乙炔流量为10sccm下制备的碳纳
米管直径分布范围最小(10～100nm), 石墨化程度最高, 缺陷密度最小, 晶形最完整. 随着乙炔流量的增大(30～90sccm), 碳纳米管的直径分布
范围增大(10～300nm), 石墨化程度降低, 缺陷密度增大, 非晶化程度增加. 因此, 通过碳源流量可以控制碳纳米管薄膜的形貌和结构.
关键词:
碳纳米管(CNTs)
,
chemical vapor deposition
,
SEM
,
TEM
,
Raman spectra
周咏东
,
金亿鑫
无机材料学报
用扫描电镜继续对发光多孔硅的阴极射线发光进行了系统的研究，得到了其阴极荧光发射部位、强度分布显微照片，发现在样品的表面层脱落处（暴露着多孔层大量微孔）无阴极射线发光产生，只有表面层未脱落处才有阴极射线发光；对样品的截面实验研究同样清楚地表明多孔硅样品的阴极射线发光只来源于其表面层，多孔层、硅单晶衬底区域不发生阴极射线发光．实验还提供了阴极射线发光强度在截面上随深度变化情况显微照片．阴极射线发光光谱表明其光谱峰值位置在680nm处，相似于多孔硅的光致发光．实验结果再次表明多孔硅的可见光来源于其表面层中的荧光物质．
关键词:
多孔硅
,
photoluminescence
,
cathodoluminescence
,
SEM
陈光华
,
吴现成
,
贺德衍
无机材料学报
采用射频等离子体增强化学气相沉积（ＣＶＤ）＋负偏压热丝辅助方法直接在Ｓｉ（１００）衬底上制备了多晶Ｃ３Ｎ４薄膜．Ｘ射线衍射测试表明，薄膜同时含有α－和β-Ｃ３Ｎ４晶相以及未知结构，没有观测到石墨衍射峰．利用扫描电子显微镜观测到线度约２μｍ、横截面为六边形的β－Ｃ３Ｎ４晶粒．纳米压痕法测得薄膜的硬度达７２．６６ ＧＰａ．
关键词:
化学气相沉积
,
C3N4
,
XRD
,
SEM
,
Hardness
胡冬力
,
邢娟娟
,
郑强
,
顾辉
,
倪德伟
,
张国军
无机材料学报
doi:10.15541/jim20140058
以两种不同WC含量、不同球磨介质的无压烧结HfB2-SiC-HfC超高温陶瓷为研究对象,对比了两套集成式相组成和相成分定量分析方法,发现基于X射线衍射和扫描电镜分析的HfB2、SiC和HfC相组成和固溶度测量结果相互符合,都适用于复相陶瓷的综合性定量分析.基于扫描电镜的分析还进一步发现和测量出痕量WB相的含量;XRD-K值法被成功应用于测量固溶度低的相组成.两个对比样品的定量分析结果表明:烧结助剂含量和球磨介质的改变都不影响W在HfB2和HfC相中的固溶度,支持了反应致密过程中液相起关键作用的观点;SiC球磨会造成W的损失,因此Si3N4是更合适的球磨介质.
关键词:
超高温陶瓷
,
X射线衍射
,
扫描电镜
,
相组成-相成分定量
,
球磨介质
X.L.Zhao1)
,
T.L.Guo2)
,
M.Ohkohchi3)
,
T.Okazaki3)
,
S.Iijima and Y.Ando3) 1) Japan Science and Technology Corporation
,
Department of Physics
,
Meijo University
,
Shiogamaguchi1 501
,
Tempaku ku
,
Nagoya 468 8502
,
Japan 2) Scientific Research Department
,
Shenyang University
,
Wanghuanan Street21
,
Dadong District
,
Shenyang 110044
,
China 3) Department of Physics
,
Meijo University
,
Shiogamaguchi 1 501
,
Tempaku ku
,
Nagoya 468 8502
,
Japan$
金属学报(英文版)
Multiwalled carbon nanotubes ( MWNTs) were prepared by DCarc dischargein hydrogen gas, and werethermally purified byinfrared radiation in air. The morphology of pristineand purified MWNTs was observed by scanning electron microscope ( SEM) , and the crys tallinestructureand perfection wereinvestigated by high resolution transmission electron mi croscope( HRTEM) and Raman spectrometer. Itcameto the conclusion thatthese MWNTs possessed a high degreeof graphitization and very narrow centralchannel(about1 0 nm indiameter) , giving risetotheappearanceof breathing modesfor MWNTs.
关键词:
multiwalled carbon nanotubes
,
null
,
null
,
null
,
null
