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991.
992.
Jin-Seung Jung Kyong-Hoon Choi Yong-Rok Kim Leszek Malkinski Weilie Zhou Charles J O'Connor 《Journal of Physics and Chemistry of Solids》2003,64(3):385-390
Superparamagnetic nickel nanoparticles were prepared by incorporating nickel ion into AlMCM41 as a nanoreactor and then reduced with sodium borohydride or H2 gas. Products were characterized by elemental analysis, transmission electron microscopy, X-ray powder diffraction, and magnetic susceptibility. The nickel particle size and blocking temperature depend on the reduction method. 相似文献
993.
994.
T. G. G. Maffeïs G. T. Owen C. Malag G. Martinelli M. K. Kennedy F. E. Kruis S. P. Wilks 《Surface science》2004,550(1-3):21-25
In this work, we report a scanning tunnelling spectroscopy (STS) study of 30 and 10 nm tin dioxide nanoparticles. The STS spectra give a surface band gap of 2.5 eV for both samples and show that the density of surface states in the band gap is around 6 times higher for the 30 nm particles than for the 10 nm particles. This provides direct experimental evidence for our theoretical model, which predicts a decrease in the surface state density as the particle size decreases, and partly accounts for the improved sensitivity of gas sensing devices fabricated with nanoparticles. 相似文献
995.
J.D. Desai 《Applied Surface Science》2006,252(23):8039-8042
Quantum dots (QDs) of iron oxide have been deposited onto ITO coated glass substrates by spray pyrolysis technique, using ferric chloride (FeCl3·7H2O) in non-aqueous medium as a starting material. The non-aqueous solvents namely methanol, ethanol, propanol, butanol and pentanol were used as solvents. The effect of solvents on the film structure and morphology was studied. The structural, morphological, compositional and optical properties were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive analysis of X-rays (EDAX), and optical absorption measurement techniques. 相似文献
996.
997.
998.
We study the concentration of adatoms on GaAs(001) during annealing under MBE conditions. By rapidly cooling the sample from typical growth temperatures and typical As overpressures, the thermal concentration of adatoms can be frozen into small islands on the terraces. The area of the resulting islands is measured with STM far from terrace steps, giving an estimate of the concentration of adatoms during equilibrium. We find that a surprisingly large concentration of adatoms is present for typical growth temperatures, e.g. 0.18 monolayer at 600°C. Possible consequences for current growth models are discussed. 相似文献
999.
G. C. Hua D. C. Grillo T. B. Ng C. C. Chu J. Han R. L. Gunshor A. V. Nurmikko 《Journal of Electronic Materials》1996,25(2):263-267
ZnMgSSe and ZnSSe layers grown on GaAs substrates with GaAs buffer layers by molecular beam epitaxy have been examined by
transmission electron microscopy (TEM). The depth level at which paired triangular stacking faults are nucleated in the ZnMgSSe/GaAs
heterostructure has been investigated by using the plan-view TEM technique. It has been found that in the ZnMgSSe/GaAs heterostructure
the nucleation of the paired stacking faults occurs within a range of depth which starts at the II-VI/GaAs interface and ends
at a level that is above the interface by about 120 nm. The dominant type of defects in ZnSSe layers, which have the single
triangular shape, has been identified to be microtwins by high resolution TEM. 相似文献
1000.
利用高分辨电子显微技术(HREM)研究了钙稀土氟碳酸盐矿物晶体结构中的混层现象,在BmSn型规则混层矿物中发现了B5S4-3R和6R两种新多型,确定了它们的晶体结构类型,晶胞参数等,揭示出B5S4规则混层矿物不同多型体的超微结构特征,讨论了B5S4-6R多型晶体结构沿C方向的无序夹层和堆垛层错等晶体缺陷现象。 相似文献