Electron-beam-directed vapor deposition of multifunctional structures for electrochemical storage

2002 ◽  
Author(s):  
Douglas T. Queheillalt ◽  
Derek D. Hass ◽  
Haydn N. G. Wadley
Keyword(s):  
Electron Beam ◽  
Vapor Deposition ◽  
Electrochemical Storage ◽  
Directed Vapor Deposition

Electron Beam - Directed Vapor Deposition of Multifunctional Structures

2001 ◽  
Vol 672 ◽  
Author(s):  
D. T. Queheillalt ◽  
Y. Katsumi ◽  
H. N. G. Wadley
Keyword(s):  
Electron Beam ◽  
Thermal Management ◽  
Metal Hydride ◽  
Vapor Deposition ◽  
Porous Electrode ◽  
Cellular Structures ◽  
Nickel Metal ◽  
Nickel Metal Hydride ◽  
Load Bearing ◽  
Directed Vapor Deposition

ABSTRACTMultifunctional structures are those that combine load bearing support in addition to supplemental functions such as actuation, electrochemical energy storage or thermal management. Electron beam - directed vapor deposition (EB- DVD) technology has been used for the deposition of templated cellular structures for micro heat-pipe structures and porous electrode coatings for rechargeable nickel - metal hydride cells. In addition to load bearing support, the tem- plated cellular structures exhibit enhanced thermal management characteristics and the electrochemical cells can be integrated into the load bearing supports of linear and truss based structures leading to their multifunctionality. Dur- ing EB-DVD, the electron beam evaporated vapor flux is encompassed by a rarefied transonic inert gas jet, entraining the vapor in a non-reactive gas flow and transporting it onto a polymer or metal template structure. Here, EB-DVD technology has been used to synthesize copper based templated cellular structures for thermal management systems and porous nickel coatings for the positive electrode of rechargeable nickel - metal hydride cells.

Synthesis of open-cell metal foams by templated directed vapor deposition

2001 ◽  
Vol 16 (4) ◽  
pp. 1028-1036 ◽  
Author(s):  
Douglas T. Queheillalt ◽  
Derek D. Hass ◽  
David J. Sypeck ◽  
Haydn N. G. Wadley
Keyword(s):  
Mechanical Properties ◽  
Electron Beam ◽  
Vapor Deposition ◽  
Transient Liquid Phase ◽  
Deposition Process ◽  
Metal Foams ◽  
Liquid Phase Sintering ◽  
Polymer Foam ◽  
Open Cell ◽  
Directed Vapor Deposition

Low-density, open-cell nickel base superalloy foams have been synthesized by a high-rate, electron beam-directed vapor deposition process and their mechanical properties evaluated. The deposition process uses an open-cell polymer foam template upon which is deposited a metal alloy coating. The electron beam evaporated flux was entrained in a rarefied transonic gas jet and propagated along the flow stream lines through the polymer structure. After vapor deposition, the polymer template was removed by low-temperature thermal decomposition. The resultant ultralightweight metal foams consisted of a three-dimensional open cell, reticulated structure possessing hollow triangular ligaments with relative densities of <3%. Their mechanical integrity was increased by either pressureless or transient liquid phase sintering. The mechanical properties of these ultralightweight metal foams were comparable to theoretical predictions for open-cell, reticulated foams.

Aspects of microanalysis in a transmission electron microscope

1978 ◽  
Vol 36 (1) ◽  
pp. 510-511
Author(s):  
R. Sinclair ◽  
B.E. Jacobson
Keyword(s):  
Grain Size ◽  
Electron Beam ◽  
Electron Microscope ◽  
Chemical Analysis ◽  
Transmission Electron Microscope ◽  
Vapor Deposition ◽  
Critical Currents ◽  
X Ray ◽  
Fine Grain ◽  
Transmission Electron

INTRODUCTIONThe prospect of performing chemical analysis of thin specimens at any desired level of resolution is particularly appealing to the materials scientist. Commercial TEM-based systems are now available which virtually provide this capability. The purpose of this contribution is to illustrate its application to problems which would have been intractable until recently, pointing out some current limitations.X-RAY ANALYSISIn an attempt to fabricate superconducting materials with high critical currents and temperature, thin Nb3Sn films have been prepared by electron beam vapor deposition [1]. Fine-grain size material is desirable which may be achieved by codeposition with small amounts of Al2O3 . Figure 1 shows the STEM microstructure, with large (∽ 200 Å dia) voids present at the grain boundaries. Higher quality TEM micrographs (e.g. fig. 2) reveal the presence of small voids within the grains which are absent in pure Nb3Sn prepared under identical conditions. The X-ray spectrum from large (∽ lμ dia) or small (∽100 Ǻ dia) areas within the grains indicates only small amounts of A1 (fig.3).

In situ study of electron beam-induced chemical vapor deposition of Au in an environmental TEM

1995 ◽  
Vol 53 ◽  
pp. 256-257
Author(s):  
J. Drucker ◽  
R. Sharma ◽  
J. Kouvetakis ◽  
K.H.J. Weiss
Keyword(s):  
Electron Beam ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Quantum Effect ◽  
Line Drawing ◽  
Chemical Vapor ◽  
Environmental Cell ◽  
Engineering Changes ◽  
Kinetics Of

Patterning of metals is a key element in the fabrication of integrated microelectronics. For circuit repair and engineering changes constructive lithography, writing techniques, based on electron, ion or photon beam-induced decomposition of precursor molecule and its deposition on top of a structure have gained wide acceptance Recently, scanning probe techniques have been used for line drawing and wire growth of W on a silicon substrate for quantum effect devices. The kinetics of electron beam induced W deposition from WF6 gas has been studied by adsorbing the gas on SiO2 surface and measuring the growth in a TEM for various exposure times. Our environmental cell allows us to control not only electron exposure time but also the gas pressure flow and the temperature. We have studied the growth kinetics of Au Chemical vapor deposition (CVD), in situ, at different temperatures with/without the electron beam on highly clean Si surfaces in an environmental cell fitted inside a TEM column.

Directed Vapor Deposition: Low Vacuum Materials Processing Technology

2000 ◽  
Author(s):  
J. F. Groves ◽  
G. Mattausch ◽  
H. Morgner ◽  
D. D. Hass ◽  
H. N. Wadley
Keyword(s):  
Vapor Deposition ◽  
Processing Technology ◽  
Materials Processing ◽  
Directed Vapor Deposition
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