排序方式: 共有29条查询结果,搜索用时 8 毫秒
1.
2.
3.
Koksal Yildiz Unal Akgul Hartmut S. Leipner Yusuf Atici 《Applied Physics A: Materials Science & Processing》2014,117(3):1387-1392
The film of thermoelectric ternary p-type (Bi0.15Sb0.85)2Te3 was deposited on polyimide foil substrate at 168 °C using direct-current magnetron sputtering. Microstructural investigations of the film were performed by electron microscopy techniques. SEM observations showed that the film surface consisted of large-sized particulates with small-sized particles and also mound-like crystal agglomerates in some areas. Chemical composition of the film was analyzed using energy-dispersive X-ray spectrometer (EDS). It has been observed that the EDS results were in an agreement with nominal composition for the film. Detailed microstructural investigations were carried out using transmission electron microscopy (TEM). TEM images and selected area electron diffraction patterns showed that the film has randomly oriented polycrystalline grain structure. High-resolution TEM images indicated that the microstructure of film also contained nano-crystal structure, smaller than 10 nm. 相似文献
4.
M. Schade O. Varlamova J. Reif H. Blumtritt W. Erfurth H. S. Leipner 《Analytical and bioanalytical chemistry》2010,396(5):1905-1911
We report on the structural investigation of self-organized periodic microstructures (ripples) generated in Si(100) targets
after multishot irradiation by approximately 100-fs to 800-nm laser pulses at intensities near the single shot ablation threshold.
Inspection by surface sensitive microscopy, e.g., atomic force microscopy (AFM) or scanning electron microscopy (SEM), and
conventional and high-resolution transmission electron microscopy reveal complex structural modifications upon interaction
with the laser: even well outside the ablated area, the target surface exhibits fine ripple-like undulations, consisting of
alternating crystalline and amorphous silicon. Inside the heavily modified area, amorphous silicon is found only in the valleys
but not on the crests which, instead, consist of highly distorted crystalline phases, rich in defects. 相似文献
5.
In many generic combustion models, one finds that a combustionwave will develop with a specific wave speed. However, thereare possible initial temperature profiles which do not evolveinto such waves, but rather die out to the ambient temperature.There can exist, in some models, a clear distinction betweenthose initial conditions that do evolve into combustion wavesand those that do not; this is sometimes referred to as thewatershed initial condition. When fuel consumption is consideredto be negligible, analytical methods can be used to obtain theexact watershed. In this paper, we consider the problem of determiningpseudo-watersheds and ascertaining the relationship betweenthese pseudo-watersheds and the exact watersheds. In the processa novel weight-function approach for infinite spatial domainsis developed. 相似文献
6.
Maurizio Roczen Enno Malguth Martin Schade Andreas Schöpke Abdelazize Laades Michael Blech Orman Gref Thomas Barthel Jan Amaru Töfflinger Manfred Schmidt Hartmut S. Leipner Lars Korte Bernd Rech 《Journal of Non》2012,358(17):2253-2256
Two different growth mechanisms are compared for the fabrication of Si/SiO2 nanostructures on crystalline silicon (c-Si) to be used as hetero-emitter in high-efficiency solar cells: (1) The decomposition of substoichiometric amorphous SiOx (a-SiOx) films with 0 < x < 1.3 and (2) the dewetting of thin amorphous silicon (a-Si) layers.The grown layers are investigated with regard to their structural properties, their passivation quality for c-Si wafer substrates and their electrical properties in order to evaluate their suitability as a nanodot hetero-emitter. While by layer decomposition, no passivating nanodots could be formed, the dewetting process allows fabricating nanodot passivation layers at temperatures as low as 600 °C. The series resistance through Ag/[Si-nanodots in SiO2]/c-Si/Al structures for dewetting is similar to nanostructured silicon rich SiOx films. Still, a nanodot hetero-emitter which exhibits both a satisfying passivation of the substrate and induces a high band bending by doping at the same time could not be fabricated yet. 相似文献
7.
Molten salt hydrates proved to be alternative solvents to cellulose. Toinvestigate the reasons for this dissolving ability, information about thesolvent–cellulose interactions is essential. As well as 13CHR NMR, 7Li NMR was used to obtain further insight into thisproblem.After comparing several molten salt hydrates, the 7Li NMR spectrarevealed a smaller shielding of the lithium cation for not dissolving than fordissolving and swelling cellulose systems. In most solvent systems theshieldingat the 7Li nuclei increases with the cellulose concentration. 2D7Li-1H HOESY NMR was successfully applied to verify thepresence of cellobiose, used as a model compound for cellulose, in the firstco-ordination sphere of the lithium cation. 相似文献
8.
9.
10.