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.

Effect of Microstructure on Phase Formation in Reaction of The Nb/Al Multilayer Thin Films

1991 ◽  
Vol 230 ◽  
Author(s):  
Katayun Barmak ◽  
Kevin R. Coffey ◽  
David A. Rudman ◽  
Simon Foner
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Phase Diagram ◽  
Grain Boundary ◽  
Phase Formation ◽  
Boundary Diffusion ◽  
Equilibrium Phase ◽  
Equilibrium Phase Diagram ◽  
Thin Layers ◽  
Multilayer Thin Films

AbstractWe investigated the phase formation sequence in the reaction of multilayer thin films of Nb/Al with overall compositions of 25 and 33 at.% AI. We report novel phenomena which distinguish thin-film reactions unequivocally from those in bulk systems. For sufficiently thin layers composition and stability of product phases are found to deviate significantly from that predicted from the equilibrium phase diagram. We demonstrate that in the Nb/Al system the length scales below which such deviations occur is about 150 nm. We believe that these phenomena occur due to the importance of grain boundary diffusion and hence microstructure in these thin films.

Reactive Phase Formation in Sputter-Deposited Ni/Al Thin Films

1995 ◽  
Vol 382 ◽  
Author(s):  
K. Barmak ◽  
C. Michaelsen ◽  
R. Bormann ◽  
G. Lucadamo
Keyword(s):  
Thin Films ◽  
Amorphous Phase ◽  
Phase Formation ◽  
Molar Ratio ◽  
Multilayer Thin Films ◽  
Nucleation Kinetics ◽  
Second Stage ◽  
Stage Process ◽  
Magnetron Sputter ◽  
Sputter Deposited

ABSTRACTWe have investigated reactive phase formation in magnetron sputter-deposited Ni/Al multilayer thin films with a 3:1 molar ratio and periodicities ranging from 2.5-320 nm. In addition, we studied the transformation of a codeposited film of the same composition. We find that an amorphous phase has already formed during deposition, and that the extentof formation of this phase increases with decreasing periodicity. The first crystalline phase then nucleates from this amorphous phase upon annealing. The formation of the amorphous phase considerably reduces the driving force and explains why during subsequent reactions nucleation kinetics become important. We obtain Ni2Al9 as the first product phase during heat treatment in some cases before NiAl3 occurs. For films with modulation periods larger than 40 nm, formation of NiAI3 is a two stage process as reported earlier, with the first stage being due to nucleation and growth to coalescence of NiAl3 grains, and the second stage being the growth of NiA13 normal to the initial interface until the reactant phases are consumed.

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.

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.

Peculiarities of Intermetallic Phase Formation in the Process of a Solid State Reaction in (Al/Cu)n Multilayer Thin Films

JOM ◽  
2021 ◽  
Author(s):  
Evgeny T. Moiseenko ◽  
Sergey M. Zharkov ◽  
Roman R. Altunin ◽  
Oleg V. Belousov ◽  
Leonid A. Solovyov ◽  
...  
Keyword(s):  
Thin Films ◽  
Solid State ◽  
Phase Formation ◽  
Solid State Reaction ◽  
Intermetallic Phase ◽  
Multilayer Thin Films

Nucleation and Growth of the First Phase in Sputter-Deposited Nb/Al Multilayer Thin Films

1995 ◽  
Vol 398 ◽  
Author(s):  
K. Barmak ◽  
S. Vivekanand ◽  
F. Ma ◽  
C. Michaelsen
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Nucleation And Growth ◽  
Grain Structure ◽  
Multilayer Thin Films ◽  
Product Phase ◽  
Scanning Calorimetry ◽  
Transmission Electron ◽  
Sputter Deposited

ABSTRACTThe formation of the first phase in the reaction of sputter-deposited Nb/Al multilayer thin films has been studied by power-compensated and heat-flux differential scanning calorimetry, x-ray diffraction and transmission electron microscopy. The modulation periods of the films are in the range of 10-500 nm. Both types of calorimetrie measurements, performed at a constant heating rate, show the presence of two peaks (A and B) for the formation of the single product phase, NbAl3. Isothermal calorimetrie scans show that peak A is associated with a nucleation and growth type transformation. The formation of NbAl3 is thus interpreted as a two-stage process of nucleation and lateral growth to coalescence (peak A) followed by normal growth until the consumption of one or both reactants (peak B). Transmission electron microscopy investigations of samples annealed into the first stage of NbAl3 formation show the presence of this phase at the Nb/Al interface and its preferential growth along the grain boundaries of the Al layer. The latter highlights the role of reactant phase grain structure in product phase formation.

Alloying process of sputter-deposited Ti/Ni multilayer thin films

2006 ◽  
Vol 438-440 ◽  
pp. 699-702 ◽  
Author(s):  
H. Cho ◽  
H.Y. Kim ◽  
S. Miyazaki
Keyword(s):  
Thin Films ◽  
Multilayer Thin Films ◽  
Sputter Deposited

Intermetallic phase formation in nanometric Ni/Al multilayer thin films

2008 ◽  
Vol 16 (9) ◽  
pp. 1061-1065 ◽  
Author(s):  
J. Noro ◽  
A.S. Ramos ◽  
M.T. Vieira
Keyword(s):  
Thin Films ◽  
Phase Formation ◽  
Intermetallic Phase ◽  
Multilayer Thin Films
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