Self-propagating, high-temperature combustion synthesis of rhombohedral AlPt thin films

2006 ◽  
Vol 21 (12) ◽  
pp. 3168-3179 ◽  
Author(s):  
D.P. Adams ◽  
M.A. Rodriguez ◽  
C.P. Tigges ◽  
P.G. Kotula
Keyword(s):  
Thin Films ◽  
High Temperature ◽  
Equilibrium Phase ◽  
Silicon Substrates ◽  
Multilayer Thin Films ◽  
Temperature Combustion ◽  
High Temperature Reactions ◽  
Sputter Deposited ◽  
Passivated Silicon ◽  
High Temperature Combustion

Sputter-deposited, Al/Pt multilayer thin films of various designs exhibited rapid, self-propagating, high-temperature reactions. With reactant layers maintained at ∼21 °C prior to ignition and films adhered to oxide-passivated silicon substrates, the propagation speeds varied from approximately 20 to 90 m/s depending on bilayer dimension and total film thickness. Contrary to current Al–Pt equilibrium phase diagrams, all multilayers reacted in air and in vacuum transformed into rhombohedral AlPt having a space group R-3(148). Rietveld refinement of AlPt powder (generated from thin film samples) yielded trigonal/hexagonal unit cell lattice parameters of a = 15.634(3) Å and c = 5.308(1) Å; the number of formula units = 39. Rhombohedral AlPt was stable to 550 °C with transformation to a cubic FeSi-type structure occurring above this temperature.

Metastable and equilibrium phase formation in sputter-deposited Ti/Al multilayer thin films

2002 ◽  
Vol 91 (12) ◽  
pp. 9575 ◽  
Author(s):  
G. Lucadamo ◽  
K. Barmak ◽  
C. Lavoie ◽  
C. Cabral ◽  
C. Michaelsen
Keyword(s):  
Thin Films ◽  
Phase Formation ◽  
Equilibrium Phase ◽  
Multilayer Thin Films ◽  
Sputter Deposited

Characterization of reactive phase formation in sputter-deposited Ni/Al multilayer thin films using TEM

1996 ◽  
Vol 54 ◽  
pp. 1000-1001
Author(s):  
G. Lucadamo ◽  
K. Barmak ◽  
C. Michaelsen
Keyword(s):  
Thin Films ◽  
Phase Formation ◽  
Dark Field ◽  
Nickel Layer ◽  
Multilayer Thin Films ◽  
Cross Sectional ◽  
Dark Field Imaging ◽  
Transmission Electron ◽  
Sputter Deposited ◽  
Constant Heating

The subject of reactive phase formation in multilayer thin films of varying periodicity has stimulated much research over the past few years. Recent studies have sought to understand the reactions that occur during the annealing of Ni/Al multilayers. Dark field imaging from transmission electron microscopy (TEM) studies in conjunction with in situ x-ray diffraction measurements, and calorimetry experiments (isothermal and constant heating rate), have yielded new insights into the sequence of phases that occur during annealing and the evolution of their microstructure.In this paper we report on reactive phase formation in sputter-deposited lNi:3Al multilayer thin films with a periodicity A (the combined thickness of an aluminum and nickel layer) from 2.5 to 320 nm. A cross-sectional TEM micrograph of an as-deposited film with a periodicity of 10 nm is shown in figure 1. This image shows diffraction contrast from the Ni grains and occasionally from the Al grains in their respective layers.

TEM studies of solid-state reactions in sputter-deposited Nb/Al multilayer thin films

1996 ◽  
Vol 54 ◽  
pp. 1020-1021
Author(s):  
F. Ma ◽  
S. Vivekanand ◽  
K. Barmak ◽  
C. Michaelsen
Keyword(s):  
Thin Films ◽  
Solid State ◽  
Stoichiometric Composition ◽  
Analytical Electron Microscopy ◽  
Grain Structure ◽  
Solid State Reactions ◽  
Multilayer Thin Films ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sputter Deposited

Solid state reactions in sputter-deposited Nb/Al multilayer thin films have been studied by transmission and analytical electron microscopy (TEM/AEM), differential scanning calorimetry (DSC) and X-ray diffraction (XRD). The Nb/Al multilayer thin films for TEM studies were sputter-deposited on (1102)sapphire substrates. The periodicity of the films is in the range 10-500 nm. The overall composition of the films are 1/3, 2/1, and 3/1 Nb/Al, corresponding to the stoichiometric composition of the three intermetallic phases in this system.Figure 1 is a TEM micrograph of an as-deposited film with periodicity A = dA1 + dNb = 72 nm, where d's are layer thicknesses. The polycrystalline nature of the Al and Nb layers with their columnar grain structure is evident in the figure. Both Nb and Al layers exhibit crystallographic texture, with the electron diffraction pattern for this film showing stronger diffraction spots in the direction normal to the multilayer. The X-ray diffraction patterns of all films are dominated by the Al(l 11) and Nb(l 10) peaks and show a merging of these two peaks with decreasing periodicity.

Development of stable supports consisting of SiCSi composite for high temperature combustion catalysts

1995 ◽  
Vol 26 (3-4) ◽  
pp. 247-254 ◽  
Author(s):  
Takeshi Okutani ◽  
Yoshinori Nakata ◽  
Masaaki Suzuki ◽  
Hideaki Nagai
Keyword(s):  
High Temperature ◽  
Temperature Combustion ◽  
High Temperature Combustion
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