Solid-state amorphization in Al–Pt thin films

1988 ◽  
Vol 3 (5) ◽  
pp. 884-889 ◽  
Author(s):  
J. M. Legresy ◽  
B. Blanpain ◽  
J. W. Mayer
Keyword(s):  
Thin Films ◽  
Solid State ◽  
Amorphous Alloy ◽  
Pure Aluminum ◽  
Alloy Layer ◽  
Hole Formation ◽  
Direct Observations ◽  
Transmission Electron ◽  
State Amorphization

Solid-state amorphization is reported to occur in aluminum-platinum thin films. A uniform amorphous alloy layer was observed at the interface between aluminum and platinum layers for electron beam evaporated samples in an as-deposited state. For a pure aluminum overlayer deposited on top of a coevaporated Al–Pt amorphous alloy, the aluminum dissolves into the amorphous phase leading to a fully amorphous sample. In this last case the amorphization is nonuniform upon low-temperature anneals (T < ≃2 200 °C) and gives rise to hole formation in the aluminum overlayer. Direct observations of this phenomenon during in situ annealing of the thin films in a transmission electron microscope were carried out.

In-situ observation of solid-state amorphization in a Ni/Ti multilayer

1990 ◽  
Vol 48 (4) ◽  
pp. 128-129
Author(s):  
Mark A. Wall ◽  
Alan F. Jankowski
Keyword(s):  
Thin Films ◽  
Solid State ◽  
Multilayered Structure ◽  
Heat Of Mixing ◽  
In Situ Observation ◽  
Composition Modulation ◽  
Low Temperature Annealing ◽  
Isothermal Anneal ◽  
State Amorphization

Solid-state amorphization between thin films of two pure crystalline metals that have a negative heat of mixing is shown by Schwartz. An isothermal anneal is used to amorphize a binary crystalline structure via interdiffusion of one species, preferentially into the other. We report a metallic-glass formation by solid state amorphization in a Ni/Ti multilayered structure by low temperature annealing in the electron microscope. TEM allows us to view the composition modulation and interfaces of the Ni/Ti multilayered structure in crossection. Crossectional TEM is regularly used to view the composition modulation and interfaces of thin films. A TEM fitted with a hot-stage sample holder makes it possible to heat the cross-sectioned multilayer in-situ and record the ensuing reaction at the Ni-Ti interfaces.Ni/Ti multilayers with a period of 26 nm (55 at.pct. Ni) were fabricated by magnetron sputtering, the details and parameters are outlined elsewhere. TEM specimens were prepared for cross-section viewing with a technique similar to Bravman and Sinclair, in combination with encapsulating the epoxied pieces with in a metal tube as described by Newcomb, et al.

The formation of amorphous Ni–B by solid state and ion-beam reaction

1989 ◽  
Vol 4 (6) ◽  
pp. 1303-1306 ◽  
Author(s):  
A. N. Campbell ◽  
J. C. Barbour ◽  
C. R. Hills ◽  
M. Nastasi
Keyword(s):  
Solid State ◽  
Amorphous Alloy ◽  
Ion Beam ◽  
Amorphous Layer ◽  
Alloy Layer ◽  
Polycrystalline Nickel ◽  
First Time ◽  
State Amorphization ◽  
Post Deposition ◽  
Beam Deposition

An amorphous Ni–B alloy was formed at the interfaces between layers of polycrystalline nickel and amorphous boron during electron-beam deposition of Ni/B/Ni trilayer structures. Formation of the amorphous alloy appears to be thermally-assisted and, in addition, the amorphous alloy regions can be extended by post-deposition ion-beam mixing. The existence of an upper limit to the thickness of the amorphous Ni–B alloy layer which forms (40 nm) indicates that the amorphous layer serves as a reaction or diffusion barrier. It has been shown for the first time that an amorphous metal-boron alloy is produced by thermal solid state amorphization reaction (SSAR).

Solid-State Amorphization in a Ti/B Multilayer

1991 ◽  
Vol 49 ◽  
pp. 904-905
Author(s):  
Alan F. Jankowski ◽  
Mark A. Wall ◽  
Daniel M. Makowiecki
Keyword(s):  
Thin Films ◽  
Solid State ◽  
The Other ◽  
Heat Of Mixing ◽  
In Situ Observation ◽  
Multilayered Structures ◽  
Adjacent Layer ◽  
Isothermal Anneal ◽  
State Amorphization

Thin films of pure crystalline metals, that have a negative heat of mixing, are known to amorphize. Solid-state amorphization reactions are possible to study using multilayered structures. The amorphization reaction is typically observed in multilayered structures in which one layer of the pair is crystalline and the adjacent layer or interface is amorphous, as in Ni/Zr and Cu/Y. The reaction progresses via a low temperature isothermal anneal (at several hundred degrees centigrade) in which one species preferentially diffuses into the other. Recently, in-situ observation of solid-state amorphization in a completely crystalline Ni/Ti multilayer indicates that nucleation of the amorphous phase occurs at incoherent crystalline interlayer boundaries. (The completely crystalline as-deposited structure was achieved by ensuring thermalization of the sputtered neutrals.) The progression of solidstate amorphization in Ti-B is examined using the multilayered configuration.

Formation and growth of an amorphous phase by solid-state reaction between GaAs and Co thin films

1991 ◽  
Vol 6 (7) ◽  
pp. 1532-1541 ◽  
Author(s):  
F-Y. Shiau ◽  
S-L. Chen ◽  
M. Loomans ◽  
Y.A. Chang
Keyword(s):  
Thin Films ◽  
Solid State ◽  
Amorphous Phase ◽  
Solid Solution Phase ◽  
Pseudobinary System ◽  
Transmission Electron ◽  
Gaas Structure ◽  
Thermodynamic Driving Force ◽  
Stability Data ◽  
State Amorphization

Solid-state amorphization reaction (SSAR) between GaAs and Co thin films was investigated by transmission electron microscopy and Auger electron spectroscopy. Upon annealing of GaAs/Co thin-film couples at 260–300 °C, an amorphous phase was observed to form. Annealing at higher temperatures or for longer times led to the crystallization of the amorphous phase into a supersaturated CoAs solid solution phase with the B31 structure. Amorphization is attributed to the rapid diffusion of Co in the rather open GaAs structure. In order to consider the thermodynamic driving force for amorphization and subsequent crystallization, the phase diagram of CoGa–CoAs was investigated using DTA and metallography. The pseudobinary system was modeled thermodynamically to yield relative stability data for the various phases between GaAs and Co. These data were used to rationalize the amorphization process.

Direct Observations of Grain Boundary Phenomena during Indentation of Al and Al-Mg Thin Films

2003 ◽  
Vol 795 ◽  
Author(s):  
W. A. Soer ◽  
J. Th. M. De Hosson ◽  
A. M. Minor ◽  
E. A. Stach ◽  
J. W. Morris
Keyword(s):  
Thin Films ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
Dislocation Dynamics ◽  
Direct Observations ◽  
Transmission Electron ◽  
The Matrix ◽  
Grain Boundary Motion

ABSTRACTThe deformation behavior of Al and Al-Mg thin films has been studied with the unique experimental approach of in-situ nanoindentation in a transmission electron microscope. This paper concentrates on the role of solute Mg additions in the transfer of plasticity across grain boundaries. The investigated Al alloys were deposited onto a Si substrate as thin films with a thickness of 200–300 nm and Mg concentrations of 0, 1.1, 1.8, 2.6 and 5.0 wt% Mg. The results show that in the Al-Mg alloys, the solutes effectively pin high-angle grain boundaries, while in pure Al considerable grain boundary motion is observed at room temperature. The mobility of low-angle grain boundaries is however not affected by the presence of Mg. In addition, Mg was observed to affect dislocation dynamics in the matrix.

Epitaxy and texture analysis of Bi-Sr-Ca-Cu-O thin films on (100) MgO using Transmission Electron Microscopy

1990 ◽  
Vol 48 (4) ◽  
pp. 68-69
Author(s):  
J. T. Sizemore ◽  
D. G. Schlom ◽  
Z. J. Chen ◽  
J. N. Eckstein ◽  
I. Bozovic ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Critical Currents ◽  
Unit Cell ◽  
X Ray Diffraction ◽  
Cell Axis ◽  
Transmission Electron ◽  
Synthesis Procedure

Investigators observe large critical currents for superconducting thin films deposited epitaxially on single crystal substrates. The orientation of these films is often characterized by specifying the unit cell axis that is perpendicular to the substrate. This omits specifying the orientation of the other unit cell axes and grain boundary angles between grains of the thin film. Misorientation between grains of YBa2Cu3O7−δ decreases the critical current, even in those films that are c axis oriented. We presume that these results are similar for bismuth based superconductors and report the epitaxial orientations and textures observed in such films.Thin films of nominally Bi2Sr2CaCu2Ox were deposited on MgO using molecular beam epitaxy (MBE). These films were in situ grown (during growth oxygen was incorporated and the films were not oxygen post-annealed) and shuttering was used to encourage c axis growth. Other papers report the details of the synthesis procedure. The films were characterized using x-ray diffraction (XRD) and transmission electron microscopy (TEM).

Phase sequence in the solid state amorphization reaction of metallic thin films

1989 ◽  
Vol 174 ◽  
pp. 11-24 ◽  
Author(s):  
S. Schneider ◽  
H. Schröder ◽  
K. Samwer ◽  
B. Schuhmacher ◽  
U. Köster
Keyword(s):  
Thin Films ◽  
Solid State ◽  
Metallic Thin Films ◽  
Phase Sequence ◽  
State Amorphization
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