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.

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.

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.

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

Fabrication of Polycrystalline Silicon on Glass from Fluorinated Precursors with the Aid of Atomic Hydrogen

1995 ◽  
Vol 403 ◽  
Author(s):  
T. Akasaka ◽  
D. He ◽  
I. Shimizu
Keyword(s):  
Thin Films ◽  
Atomic Hydrogen ◽  
Polycrystalline Silicon ◽  
In Situ Observation ◽  
Layer By Layer ◽  
High Quality ◽  
Deposition Parameters ◽  
Columnar Grains ◽  
Step Growth

AbstractHigh quality polycrystalline silicon was made on glass from fluorinated precursors by two step growth, i.e., (1) formation of seed crystals on glass by layer-by-layer(LL) technique and (2) grain-growth on the seeds. In LL technique, deposition of ultra-thin films and treatment with atomic hydrogen was repeated alternately. Columnar grains with 200 nm dia were grown epitaxy-like on the seeds by optimizing the deposition parameters under in situ observation with spectroscopic ellipsometry.

Study on preparing PLT(28) thin film and its electro-optic effect

1998 ◽  
Vol 13 (5) ◽  
pp. 1266-1270 ◽  
Author(s):  
Ai-Li Ding ◽  
Wei-Gen Luo ◽  
P. S. Qiu ◽  
J. W. Feng ◽  
R. T. Zhang
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Magnetron Sputtering ◽  
Faraday Effect ◽  
The Other ◽  
Ceramic Powders ◽  
Glass Substrates ◽  
Annealing Conditions ◽  
Electro Optic

PLT(28) thin films deposited on glass substrates were studied by two sputtering processes. One is an in situ magnetron sputtering and the other is a low-temperature magnetron sputtering. The sintered PLT ceramic powders are used as a sputtering target for both processes. The influences of sputtering and annealing conditions on structure and crystallinity of the films were investigated. The electro-optic (E-O) properties of PLT(28) thin films prepared by the two processes were determined by a technique according to Faraday effect. The researches showed the E-O properties were strongly affected by the sputtering process. The film with larger grains exhibits stronger E-O effect. The quadratic E-O coefficient of PLT(28) thin film varies in the range of 0.1 × 10−16 to 1.0 × 10−16 (m/v)2.

Solid state amorphization reactions in deformed Ni-Zr multilayered composites

1990 ◽  
Vol 5 (3) ◽  
pp. 488-497 ◽  
Author(s):  
G. C. Wong ◽  
W. L. Johnson ◽  
E. J. Cotts
Keyword(s):  
Thermal Stability ◽  
Solid State ◽  
Amorphous Phase ◽  
Equilibrium Phase ◽  
Solid State Reactions ◽  
Heat Of Mixing ◽  
Scanning Calorimetry ◽  
Multilayered Composites ◽  
State Amorphization ◽  
Thermal Stability Of

The mechanisms of metallic glass formation and competing crystallization processes in mechanically-deformed Ni-Zr multilayered composites have been investigated by means of differential scanning calorimetry and x-ray diffraction. Our investigation of the heat of formation of amorphous NixZr1−x alloys shows a large negative heat of mixing (on the order of 30 kJ/mole) for compositions near Zr55Ni45 with a compositional dependence qualitatively similar to that predicted by mean field theory. We find that the products of solid state reactions in composites of Ni and Zr can be better understood in terms of the equilibrium phase diagram and the thermal stability of liquid quenched metallic glasses. We have determined the composition of the growing amorphous phase at the Zr interface in these Ni-Zr diffusion couples to be 55 ± 4% Zr. We investigated the kinetics of solid state reactions competing with the solid state amorphization reaction and found the value of the activation energy of the initial crystallization and growth of the growing amorphous phase to be 2.0 ± 0.1 eV, establishing an upper limit on the thermal stability of the growing amorphous phase.

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