Rare earth ions and Ge nanocrystals in SiO2
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Experimental studies of Ge nanocrystals embedded in SiO2 films doped with Er and Yb deposited by rf-magnetron sputtering are presented. Although inter-band photoluminescence (PL) from the Ge nanocrystals is not observed, it is nevertheless found that the presence of Ge nanocrystals is crucial for obtaining light emission from Er3+ and Yb3+. For both kinds of rare earth ions, the intensity of the related PL line has a maximum after heat treatment at 800 °C, and the PL excitation spectra for the two cases are very similar. This suggests that the presence and the structure of the nanocrystals are important for the efficiency of PL from Er3+ and Yb3+. Experiments performed with multilayer structures of Ge nanocrystals and SiO2 show that the optically active rare earth ions are located in the SiO2 layers, and not inside the Ge nanocrystals. The mechanism of energy transfer from Ge nanocrystals to the rare earth ions is found to be non-optical.Inert
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The SiO2 sputtering yield was determined for 170–300 keV He+ ion bombardment. The low sputtering efficiency and blistering at high ion doses make high-energy He+ ion sputtering yields difficult to determine, but by modifying a measurement method previously used for heavy ions, the sputtering yield could be quite accurately determined after sputtering only 20 Å of SiO2. The sputtering yield was found not to be proportional to the energy deposited by the ion in elastic collisions at the surface of SiO2. Comparison with SiO2 sputtering yields found in literature shows that the sputtering yield increases with increasing energy deposited in electronic excitations for similar energy deposited in elastic collisions, indicating that electronic effects probably have to be included in the description of the sputtering process. Since the electronic effects do not seem to be independent of the sputtering by elastic collisions, it is suggested that SiO2 sputtering be controlled by a mixed collisional-electronic mechanism. Sputtering yield measurements were also performed for varying angles of ion incidence and, here also, good agreement could be achieved with predictions based on a mixed sputtering mechanism.
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The computer program is prepared for applying Montecarlo simulation and modeling for single-electron nanocrystal memories. The nanocrystal memory device of (5×5) quantum dots is used for studying the relationship between, geometrical dimensions, electrical characteristics and charging effects for single electron static programming characteristics. The nanocrystal inter-dot effects are included. All parameters got in the memory simulation programming are studied and discussed. Keywords: Nanocrystal Memories.
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Component (thermodynamics)
Transient (computer programming)
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The electronic properties of metal nanocrystal quantum dot solids in the insulating state have been measured as a function of nanocrystal diameter under conditions of controlled inter-nanocrystal separation. Such properties of these weakly coupled nanocrystal arrays (see image), in particular the array charging energy, can be manipulated through experimental control of the nanocrystal diameter and mean inter-nanocrystal separation.
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New simulation results for the sputtering of lunar soil surface by solar-wind protons and heavy ions will be presented. Previous simulation results showed that the sputtering process has significant effects and plays an important role in changing the surface chemical composition, setting the erosion rate and the sputtering process timescale. In this new work and in light of recent data, we briefly present some theoretical models which have been developed to describe the sputtering process and compare their results with recent calculation to investigate and differentiate the roles and the contributions of potential (or electrodynamic) sputtering from the standard (or kinetic) sputtering.
Regolith
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这里，我们在水晶的结构(nanocrystallinity ) 或公司 nanocrystals 的涂层代理人的长度导致的 500-nm-thick Co-nanocrystal 3D 超点阵(supracrystals ) 的层次机械行为上报导。通过他们的 nanocrystallinities 的控制增加公司 nanocrystals 的 nanocrystal 形状 anisotropy 导致订与的高水平翻译并且在 supracrystals 以内的 nanocrystals 的 orientational 排列。在在各种各样的规模订的层次，即从在到在 supracrystals 以内的 nanocrystal 超点阵的 nanocrystals 以内的原子格子，在 supracrystals 的幼仔模量与显著变化被相关：从 0.7？？
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Crystal (programming language)
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