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991.
Using analytical transmission electron microscopy (TEM) techniques reveal a zigzag layer on surface of the cycled particles of LiNi1/3Co1/3Mn1/3O2 cathode after 300 discharge/charge cycles. The Ni, Mn content in the zigzag layer of the cycled particle has decreased rapidly from interior to edge of the zigzag layer of the cycled particles. The structure of LiNi1/3Co1/3Mn1/3O2 oxide was gradually destructed from hexagonal cell with P3112 at interior region to fcc lattice of α-NaFeO2 at edge of the zigzag layer of the cycled particles. These experimental data provide the compositional and structural origins of the capacity decrease in the Li-ion battery. 相似文献
992.
采用一种以醇盐水解法为基础的生长硅溶胶的方法,制备了粒径为200nm的单分散二氧化硅球形颗粒,并将其作为核心,利用常温连续进料的钛酸丁酯水解的多步法,在二氧化硅核心外经多次包覆形成厚层二氧化钛;在正硅酸乙酯的水解和陈化环境下,将上述TiO2/SiO2复合颗粒外再包覆一薄层二氧化硅,形成一种高折射率,可用于组装光子晶体的SiO2/TiO2/SiO2多层复合微球.对该复合微球用重力沉降法、透射电镜法(TEM)、X射线能谱分析法(EDS)进行了表征.其中,重力沉降法是一种将Stokes公式为基础推导的复合颗粒的粒径与沉降速度关系式所得的一系列数据进行拟合外延,来测定复合颗粒的粒径及包覆厚度的方法. 相似文献
993.
采用金相和透射电镜衍衬分析技术研究了 Fe- 6.5Si合金在 2 0 0℃温度下拉伸时的塑性变形行为。结果表明 ,在 2 0 0℃温度下拉伸时 ,该合金的 {1 1 0 }〈1 1 1〉滑移系开动 ,从而在合金中形成形变带。 相似文献
994.
J. Y. Dai K. K. Ong D. Z. Chi M. H. Liang K. C. Leong L. Chan S. K. Lahiri 《Journal of Electronic Materials》2001,30(7):850-854
Effects of temperature and dosage on the evolution of extended defects during annealing of MeV ion-implanted Czochralski (CZ)
p-type (001) silicon have been studied using transmission electron microcopy. Excess interstitials generated in a 1 1015 cm−2/1.5 MeV B+ implanted Si have been found to transform into extended interstitial {311} defects upon rapid thermal annealing at 800°C
for 15 sec. During prolonged furnace annealing at 960°C for 1 h, some of the {311} defects grow longer at the expense of the
smaller ones, and the average width of the defects seems to decrease at the same time. Formation of stable dislocation loops
appears to occur only above a certain threshold annealing temperature (∼1000°C). The leakage current in diodes fabricated
on 1.5 MeV B+ implanted wafers was found to be higher for a dosage of 1 1014cm−2 and less, as compared to those fabricated with a dosage of 5 1014 cm−2 and more. The difference in the observed leakage current has been attributed to the presence of dislocations in the active
device region of the wafers that were implanted with the lower dosage. 相似文献
995.
Hyung Koun Cho Jeong Yong Lee Chi Sun Kim Gye Mo Yang 《Journal of Electronic Materials》2001,30(10):1348-1352
We have studied the influence of indium (In) composition on the structural and optical properties of Inx Ga1−xN/GaN multiple quantum wells (MQWs) with In compositions of more than 25% by means of high-resolution x-ray diffraction (HRXRD),
photoluminescence (PL), and transmission electron microscopy (TEM). With increasing the In composition, structural quality
deterioration is observed from the broadening of the full width athalf maximum of the HRXRD superlattice peak, the broad multiple
emission peaks oflow temperature PL, and the increase of defect density in GaN capping layers and InGaN/GaN MQWs. V-defects,
dislocations, and two types of tetragonal shape defects are observed within the MQW with 33% In composition by high resolution
TEM. In addition, we found that V-defects result in different growth rates of the GaN barriers according to the degree of
the bending of InGaN well layers, which changes the period thickness of the superlattice and might be the source of the multiple
emission peaks observed in the InxGa1−xN/GaN MQWs with high in compositions. 相似文献
996.
The application of the strain induced lateral ordering process to the strain-compensated (Ga0.22In0.78As)m (Ga0.22In0.78P)m short period superlattices is investigated. The superlattices have been grown at low temperatures by solid source molecular
beam epitaxy (MBE) on (001) InP. These superlattices have been used in multiquantum well heterostructures using InP as barriers.
The anisotropic polarization of photoluminescence shows the existence of lateral modulation. Dark-field images using the 220
reflection gives modulated contrast in the superlattice layers. High-resolution transmission electron microscopy shows local
variations of the interplanar spacing of the (200) planes as well as the angles they form with the (002) planes. 相似文献
997.
M. Lei H.Z. Zhao H. Yang B. Song L.Z. Cao P.G. Li W.H. Tang 《Journal of Alloys and Compounds》2008,460(1-2):130-137
We design a facile and efficient solid-state reaction method by selecting an organic reagent dicyandiamide and metal oxides as precursors to prepare metal nitrides, carbides and rare-earth metal dioxymonocarbodiimides in sealed ampoules. Some fine divided nitride and carbide nanoparticles with small and uniform size can be easily obtained at the relatively low temperatures. It is interesting to find that dicyandiamide is not only a highly efficient nitridation reagent but also a highly efficient carburization reagent, and can be used as a precursor to directly synthesize rare-earth metal dioxymonocarbodiimides. A possible mechanism is proposed to explain the results of the reactions between the organic reagent and metal oxides. 相似文献
998.
Nobuko Hanada Enoki Hirotoshi Takayuki Ichikawa Etsuo Akiba Hironobu Fujii 《Journal of Alloys and Compounds》2008,450(1-2):395-399
The microstructures of MgH2 catalyzed with Ni nano-particle or Nb2O5 mesoporous powders are examined by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) observations. For MgH2 catalyzed with Ni, the Ni particles with the diameter smaller than 1 μm were detected on the MgH2 particles with the diameter smaller than 5 μm by the back scattering electron (BSE) microscopy. In details, the TEM micrograph indicates that the Ni particles distribute 20 nm in diameter on MgH2 uniformly, which was the same size as the additive doped in MgH2 before milling. On the other hand, for MgH2 catalyzed with Nb2O5, the additive particles could not be found anywhere in the BSE image. Even in the TEM micrograph by much larger magnification than the SEM micrograph, the particles corresponding to the additive cannot be observed at all. Furthermore, an energy dispersive X-ray (EDX) analysis in spots with a diameter of 20 nm indicated that the existing ratio of Mg to Nb was evaluated to 98:2, being the same as the starting ratio before milling. Therefore, the metal oxide Nb2O5 becomes extremely small particle that could not be observed by the present work after milling compared to metal Ninano. 相似文献
999.
采用透射电子显微镜(TEM)研究了两相钛合金Ti-700在不同热处理制度下的显微组织和相结构.探讨了固溶温度,冷却方式以及时效处理对显微结构的影响.结果表明,在所选择的热处理制度下,合金为双态组织,除了基体(α β)外,还发现了α2相以及调质结构.这些析出物对Ti-700钛合金的性能有一定影响. 相似文献
1000.