scholarly journals Формирование наночастиц Au и особенности травления подложки Si после облучения атомарными и молекулярными ионами

Author(s):  
М.С. Тужилкин ◽  
П.Г. Беспалова ◽  
М.В. Мишин ◽  
И.Е. Колесников ◽  
К.В. Карабешкин ◽  
...  

Formation of metal nanoparticles on silicon substrate by thin gold film irradiation with accelerated atomic and molecular ions is shown. Structures obtained were etched by metal-assisted catalytic chemical technique to get porous silicon structure. Size of gold nanoparticles and the structure of porous siliconstrongly depend on kind of incident species and ion dose. A local increase in the energy release density at the target surface that takes place during molecular ion bombardment significantly reduce the doses required for the formation of predetermined film morphology and the distribution of nanoparticles on the surface, while at the same time molecules exhibit lower radiation effect on the substrate. Luminescent properties of porous silicon do not depend on the kind of ion used, and can be tuned by composition of an etching solution

2019 ◽  
Author(s):  
Kam Sang Kwok ◽  
Yuxuan Wang ◽  
Michael Cao ◽  
Hao Shen ◽  
Weinan Xu ◽  
...  

<p>The local structure and geometry of catalytic interfaces can influence the selectivity of chemical reactions. Here, using a pre-strained polymer, we uniaxially compress a thin gold film to form a nano-folded catalyst. We observe two kinds of folds and can tune the ratio of loose to tight folds by varying the extent of pre-strain in the polymer. We characterize the nano-folded catalysts using x-ray diffraction, scanning, and transmission electron microscopy. We observe grain reorientation and coarsening in the nano-folded gold catalysts. Electroreduction of carbon dioxide with these nano-folded catalysts reveals an enhancement of Faradaic efficiency for carbon monoxide formation by a factor of about four. This result suggests that electrolyte mass transport limitations and an increase of the local pH in the tight folds of the catalyst outweigh the effects of alterations in grain characteristics. Together, our studies demonstrate that nano-folded geometries can significantly alter grain characteristics, mass transport, and catalytic selectivity. </p>


2002 ◽  
Vol 80 (20) ◽  
pp. 3715-3717 ◽  
Author(s):  
Ulrich C. Fischer ◽  
Eugene Bortchagovsky ◽  
Jörg Heimel ◽  
René T. Hanke

2002 ◽  
Vol 34 (3) ◽  
pp. 199-202 ◽  
Author(s):  
K. Venkatakrishnan ◽  
B. Tan ◽  
B.K.A. Ngoi

Vacuum ◽  
1994 ◽  
Vol 45 (2-3) ◽  
pp. 299-301 ◽  
Author(s):  
L. Stobiński ◽  
R. Duś

Author(s):  
Weigang Ma ◽  
Haidong Wang ◽  
Xing Zhang ◽  
Wei Wang

How the energy transfers during electron-phonon nonequilibrium in thin metal films is still an open question, and how to measure the intrinsic thermal transport properties of the material under the covering layer is another challenge. In this paper, the heat transfer process from electron-phonon nonequilibrium in thin gold film to borosilicate glass substrate has been studied by resorting to different segments of the transient thermoreflectance signal, which is obtained from the rear-pump front-probe transient thermoreflectance technique. The gold film, which has a thickness of 23.1 nm, is deposited on the borosilicate glass substrate using using a physical vapor deposition (PVD) approach. Within the framework of the two-temperature model (TTM), the electron-phonon (e-ph) coupling factors of the gold film, which reflect the strength of heat flow from hot electrons to cold phonons, are derived from the signal taken after the first several picoseconds with different pump fluences, and the measured value is (1.95–2.05)×1016 W m−3 K−1. The electron-phonon coupling factor does not significantly change in response to the pump pulse fluence variation and exhibits little change compared to the bulk gold value 2.4×1016 W m−3 K−1. Furthermore, the thermal conductivity of the glass substrate is obtained through the thermoreflectance signal between 20 to 140 picoseconds and the value is W m−1 K−1.


Surface ◽  
2018 ◽  
Vol 10(25) ◽  
pp. 37-50
Author(s):  
V. I. Grigoruk ◽  
◽  
V. I. Kanevskii ◽  
S. A. Kolenov ◽  
◽  
...  

Sign in / Sign up

Export Citation Format

Share Document