Composition and Structure Control of Cu–Al–O Films Prepared by Reactive Sputtering and Annealing

2007 ◽  
Vol 46 (1) ◽  
pp. 351-355 ◽  
Author(s):  
Nozomu Tsuboi ◽  
Yuji Itoh ◽  
Junya Ogata ◽  
Satoshi Kobayashi ◽  
Hidehiko Shimizu ◽  
...  
Keyword(s):  
Reactive Sputtering ◽  
Structure Control ◽  
Composition And Structure

Effect of reactive gas mass flow on the composition and structure of AIN films deposited by reactive sputtering

1993 ◽  
Vol 230 (2) ◽  
pp. 121-127 ◽  
Author(s):  
E.J.-Bienk ◽  
H. Jensen ◽  
G.N. Pedersen ◽  
G. Sørensen
Keyword(s):  
Mass Flow ◽  
Reactive Sputtering ◽  
Composition And Structure ◽  
Reactive Gas

Hierarchical Modeling of HLW Glass-Gel-Solution Systems for Stage 3 Glass Degradation

2015 ◽  
Vol 1744 ◽  
pp. 173-184 ◽  
Author(s):  
Carol M. Jantzen ◽  
Charles L. Crawford
Keyword(s):  
Hierarchical Modeling ◽  
A Priori ◽  
Reaction Products ◽  
Secondary Phases ◽  
Strong Base ◽  
Structure Control ◽  
Gel Layer ◽  
Composition And Structure ◽  
High Level ◽  
Accelerated Leaching

ABSTRACTThe necessity to a priori predict the durability of high level nuclear waste (HLW) glasses on extended time scales has led to a variety of modeling approaches based primarily on solution (leachate) concentrations. The glass composition and structure control the leachate and the gel compositions which in turn control what reaction products form: the leached layer is a hydrogel and reacts with the solution (leachate) to form secondary phases some of which cause accelerated glass dissolution which is undesirable. Glasses with molar excess alkali that is not bound to glass forming (Al,Fe,B)O4 structural groups in the glass resume accelerated leaching. The hydrogels of the glasses that resume accelerated leaching at long times contain excess alkali and the leachates contain excess strong base, [SB]ex. The [SB]ex further accelerates aluminosilicate gel aging into analcime with time. Glasses with no excess molar structural alkali do not resume accelerated leaching: the glass generates weak acids, [WA], in the leachate favoring hydrogel aging into clays. These data indicate that the gel layer transforms to secondary phases in situ in response to interactions with the chemistry of a continuously evolving leachate.

Composition and structure control of ultralight graphene foam for high-performance microwave absorption

Carbon ◽  
2016 ◽  
Vol 105 ◽  
pp. 438-447 ◽  
Author(s):  
Yi Zhang ◽  
Yi Huang ◽  
Honghui Chen ◽  
Zhiyu Huang ◽  
Yang Yang ◽  
...  
Keyword(s):  
Microwave Absorption ◽  
High Performance ◽  
Graphene Foam ◽  
Structure Control ◽  
Composition And Structure

Composition and Structure Characterization of WNx Films Produced by RF Reactive Sputtering

1990 ◽  
Vol 187 ◽  
Author(s):  
Dongliang Lin ◽  
Bewda Yan ◽  
Weili Yu
Keyword(s):  
Partial Pressure ◽  
Pressure Ratio ◽  
Reactive Sputtering ◽  
Structure Characterization ◽  
Working Pressure ◽  
Composition And Structure ◽  
Crystalline Films ◽  
Deposited Film ◽  
Partial Pressure Ratio

AbstractWNx film is one of the most promising materials for self-aligned GaAs NASFET because of its low electrical resistivity and high Schottky Barrier Height at the WNx /GaAs contact.In this paper, the effect of the sputtering conditions and the annealing environment on the chemical composition and structure of the WNx films deposited on Si and GaAs by RF reactive sputtering are studied.The results show that with the increase of the partial pressure ratio of nitrogen gas or decrease of the working pressure, deposition rate of WNx film decreases, whereas the atomic percentage of N in the deposited film increases before approaching saturation. The WNx films formed at high working pressure (≈5 × 10−2 torr) consist of W, WN or W2N phases depending on the nitrogen partial pressure ratio. Whereas the films formed at low working pressure (≈ 3 × 10−3 torr) are usually amorphous. Annealing in a flowing N2 gas causes the crystallization of the amorphous films, which mainly consist of W+W2N. There is no change for the crystalline films. However, annealing in H2 gas causes severe loss of nitrogen of the film, the film becoming single W phase eventually.

Crystal Structure Analysis of Cu-Zr Alloys by Convergent Beam Diffraction

1981 ◽  
Vol 39 ◽  
pp. 354-355
Author(s):  
A. F. Marshall ◽  
J. W. Steeds ◽  
D. Bouchet ◽  
S. L. Shinde ◽  
R. G. Walmsley
Keyword(s):  
Crystal Structure ◽  
Point Group ◽  
Intermetallic Phase ◽  
Three Dimensional ◽  
Crystal Structure Analysis ◽  
Ion Milling ◽  
Composition And Structure ◽  
Unit Cells ◽  
Sputter Deposited ◽  
Convergent Beam

Convergent beam electron diffraction is a powerful technique for determining the crystal structure of a material in TEM. In this paper we have applied it to the study of the intermetallic phases in the Cu-rich end of the Cu-Zr system. These phases are highly ordered. Their composition and structure has been previously studied by microprobe and x-ray diffraction with sometimes conflicting results.The crystalline phases were obtained by annealing amorphous sputter-deposited Cu-Zr. Specimens were thinned for TEM by ion milling and observed in a Philips EM 400. Due to the large unit cells involved, a small convergence angle of diffraction was used; however, the three-dimensional lattice and symmetry information of convergent beam microdiffraction patterns is still present. The results are as follows:1) 21 at% Zr in Cu: annealed at 500°C for 5 hours. An intermetallic phase, Cu3.6Zr (21.7% Zr), space group P6/m has been proposed near this composition (2). The major phase of our annealed material was hexagonal with a point group determined as 6/m.

Off-axis electron holography applied to the study of interfaces

1992 ◽  
Vol 50 (1) ◽  
pp. 244-245
Author(s):  
J.K. Weiss ◽  
M. Gajdardziska-Josifovska ◽  
M. R. McCartney ◽  
David J. Smith
Keyword(s):  
Electric Fields ◽  
Resolution Enhancement ◽  
Interfacial Structure ◽  
Atomic Scale ◽  
Bulk Property ◽  
Electron Holography ◽  
Specimen Thickness ◽  
Composition And Structure ◽  
Chemical Segregation ◽  
Diffraction Effects

Interfacial structure is a controlling parameter in the behavior of many materials. Electron microscopy methods are widely used for characterizing such features as interface abruptness and chemical segregation at interfaces. The problem for high resolution microscopy is to establish optimum imaging conditions for extracting this information. We have found that off-axis electron holography can provide useful information for the study of interfaces that is not easily obtained by other techniques.Electron holography permits the recovery of both the amplitude and the phase of the image wave. Recent studies have applied the information obtained from electron holograms to characterizing magnetic and electric fields in materials and also to atomic-scale resolution enhancement. The phase of an electron wave passing through a specimen is shifted by an amount which is proportional to the product of the specimen thickness and the projected electrostatic potential (ignoring magnetic fields and diffraction effects). If atomic-scale variations are ignored, the potential in the specimen is described by the mean inner potential, a bulk property sensitive to both composition and structure. For the study of interfaces, the specimen thickness is assumed to be approximately constant across the interface, so that the phase of the image wave will give a picture of mean inner potential across the interface.

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