scholarly journals Morphological Tuning of Nanoporous Metals Prepared with Conversion Reaction Synthesis via Thermal Annealing

2019 ◽  
Vol 123 (29) ◽  
pp. 17873-17883 ◽  
Author(s):  
Christopher M. Coaty ◽  
Adam A. Corrao ◽  
Victoria Petrova ◽  
Peter G. Khalifah ◽  
Ping Liu
Nanoscale ◽  
2021 ◽  
Author(s):  
Christopher M. Coaty ◽  
Adam A. Corrao ◽  
Victoria Petrova ◽  
Taewoo Kim ◽  
David P. Fenning ◽  
...  

Conversion reaction synthesis methods yield a nanoporous ZnO-supported Co catalyst with an anisotropic crystal structure and an anisotropic, hierarchical, columnar wall morphology that is highly efficient for steam reforming of ethanol to produce H2.


Author(s):  
Robert C. Rau ◽  
John Moteff

Transmission electron microscopy has been used to study the thermal annealing of radiation induced defect clusters in polycrystalline tungsten. Specimens were taken from cylindrical tensile bars which had been irradiated to a fast (E > 1 MeV) neutron fluence of 4.2 × 1019 n/cm2 at 70°C, annealed for one hour at various temperatures in argon, and tensile tested at 240°C in helium. Foils from both the unstressed button heads and the reduced areas near the fracture were examined.Figure 1 shows typical microstructures in button head foils. In the unannealed condition, Fig. 1(a), a dispersion of fine dot clusters was present. Annealing at 435°C, Fig. 1(b), produced an apparent slight decrease in cluster concentration, but annealing at 740°C, Fig. 1(C), resulted in a noticeable densification of the clusters. Finally, annealing at 900°C and 1040°C, Figs. 1(d) and (e), caused a definite decrease in cluster concentration and led to the formation of resolvable dislocation loops.


2003 ◽  
Vol 27 (11) ◽  
pp. 1083-1086 ◽  
Author(s):  
H. Ito ◽  
T. Kusunoki ◽  
H. Saito ◽  
S. Ishio

Author(s):  
Satoshi Taniguchi ◽  
Norihiko Yamaguchi ◽  
Takao Miyajima ◽  
Masao Ikeda

2002 ◽  
Vol 716 ◽  
Author(s):  
G.Z. Pan ◽  
E.W. Chang ◽  
Y. Rahmat-Samii

AbstractWe comparatively studied the formation of ultra thin Co silicides, Co2Si, CoSi and CoSi2, with/without a Ti-capped and Ti-mediated layer by using rapid thermal annealing in a N2 ambient. Four-point-probe sheet resistance measurements and plan-view electron diffraction were used to characterize the silicides as well as the epitaxial characteristics of CoSi2 with Si. We found that the formation of the Co silicides and their existing duration are strongly influenced by the presence of a Ti-capped and Ti-mediated layer. A Ti-capped layer promotes significantly CoSi formation but suppresses Co2Si, and delays CoSi2, which advantageously increases the silicidation-processing window. A Ti-mediated layer acting as a diffusion barrier to the supply of Co suppresses the formation of both Co2Si and CoSi but energetically favors directly forming CoSi2. Plan-view electron diffraction studies indicated that both a Ti-capped and Ti-mediated layer could be used to form ultra thin epitaxial CoSi2 silicide.


2003 ◽  
Vol 766 ◽  
Author(s):  
Raymond N. Vrtis ◽  
Mark L. O'Neill ◽  
Jean L. Vincent ◽  
Aaron S. Lukas ◽  
Brian K. Peterson ◽  
...  

AbstractWe report on our work to develop a process for depositing nanoporous organosilicate (OSG) films via plasma enhanced chemical vapor deposition (PECVD). This approach entails codepositing an OSG material with a plasma polymerizable hydrocarbon, followed by thermal annealing of the material to remove the porogen, leaving an OSG matrix with nano-sized voids. The dielectric constant of the final film is controlled by varying the ratio of porogen precursor to OSG precursor in the delivery gas. Because of the need to maintain the mechanical strength of the final material, diethoxymethylsilane (DEMS) is utilized as the OSG precursor. Utilizing this route we are able to deposit films with a dielectric constant of 2.55 to 2.20 and hardness of 0.7 to 0.3 GPa, respectively.


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