Kinetics of Metallic Glass Formation by Solid State Reactions

1985 ◽  
Vol 57 ◽  
Author(s):  
K. Samwer ◽  
H Schröder ◽  
M. Moske
Keyword(s):  
Electron Microscopy ◽  
Solid State ◽  
Metallic Glass ◽  
Glass Formation ◽  
Amorphous Layer ◽  
Solid State Reactions ◽  
Diffusion Couples ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Kinetics Of

AbstractMetallic glass formation by solid state reactions has been observed in multilayer Zr-Co diffusion couples. The kinetics of the reaction are limited by the diffusion of the Co-atoms in the growing amorphous layer, at least for longer times, as shown by cross-sectional transmission electron microscopy and resistance measurements. The latter one provides the interdiffusion constant and the activation energy of about 1.1 eV. Deposition of the crystalline layers at 77 K results in an enhanced amorphization process in the first stage of the reaction and gives preliminary answers about the nucleation of the amorphous phase.

Kinetics of the solid-state reaction for the formation of amorphous ZrCo studied by electrical conductance measurements

1988 ◽  
Vol 3 (3) ◽  
pp. 461-465 ◽  
Author(s):  
H. Schröder ◽  
K. Samwer
Keyword(s):  
Thin Film ◽  
Electron Microscopy ◽  
Solid State ◽  
Solid State Reaction ◽  
Linear Time ◽  
Electrical Conductance ◽  
Reaction Times ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Kinetics Of

Thin-film reactions of Co with Zr have been studied in the temperature range between 473 and 523 K by electrical conductance measurements and cross-sectional transmission electron microscopy (CS-TEM). The reduction of the electrical conductance during the solid state reaction is explained by formation and growth of an amorphous phase at every Zr/Co interface. For long reaction times the growth of the layer thickness follows a shifted $\sqrt t$ law. For short reaction times the measurements show a linear time law, which is expected for an interface limited reaction.

Non-Alloyed Ohmic Contacts to n-GaAs Using Epitaxial Ge Layers

1985 ◽  
Vol 54 ◽  
Author(s):  
T. Sawada ◽  
W. X. Chen ◽  
E. D. Marshall ◽  
K. L. Kavanagh ◽  
T. F. Kuech ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Solid State ◽  
Ohmic Contacts ◽  
Solid Phase ◽  
Solid State Reactions ◽  
Solid Phase Epitaxy ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Shallow Junctions

ABSTRACTAlloyed ohmic contacts (i.e. Au-Ge-Ni) to n-GaAs lead to non-planar interfaces which are unsuitable for devices with shallow junctions and small dimensions. In this study, the fabrication of non-alloyed ohmic contacts (via solid state reactions) is investigated. A layered structure involving the solid phase epitaxy of Ge using a transport medium (PdGe) is shown to produce low (1 — 5 × 10∼6Ω cm2) and reproducible values of contact resistivity. The resultant interface is shown to be abrupt by cross-sectional transmission electron microscopy.

In-Situ Annealing Transmission Electron Microscopy Study of Pd/Ge/Pd/GaAs Interfacial Reactions

1999 ◽  
Vol 589 ◽  
Author(s):  
F. Radulescu ◽  
J.M. Mccarthy ◽  
E. A. Stach
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Solid State ◽  
Epitaxial Growth ◽  
Ohmic Contact ◽  
Ion Beam ◽  
Solid State Reactions ◽  
Cross Sectional ◽  
Transmission Electron

AbstractIn-situ TEM annealing experiments on the Pd (20 nm) / a-Ge (150 nm) / Pd (50 nm) GaAs ohmic contact system have permitted real time determination of the evolution of contact microstructure. As-deposited cross-sectional samples of equal thickness were prepared using a focused ion beam (FIB) method and then subjected to in-situ annealing at temperatures between 130-400 °C. Excluding Pd-GaAs interactions, four sequential solid state reactions were observed during annealing of the Pd:Ge thin films. First, interdiffusion of the Pd and Ge layers occurred, followed by formation of the hexagonal Pd2Ge phase. This hexagonal phase then transformed into orthorhombic PdGe, followed by solid state epitaxial growth of Ge at the contact / GaAs interface. The kinetics of the solid state reactions, which occur during ohmic contact formation, were determined by measuring the grain growth rates associated with each phase from the videotape observations. These data agreed with a previous study that measured the activation energies through a differential scanning calorimetry (DSC) method. We established that the Ge transport to the GaAs interface was dependent upon the grain size of the PdGe phase. The nucleation and growth of this phase was demonstrated to have a significant effect on the solid phase epitaxial growth of Ge on GaAs. These findings allowed us to engineer an improved two step annealing procedure that would control the shape and size of the PdGe grains. Based on these results, we have established the suitability of combining FIB sample preparation with in-situ cross-sectional transmission electron microscopy (TEM) annealing for studying thin film solid-state reactions.

Kinetic and Thermodynamic Aspects of Phase Evolution in Ti/a-Si Multilayer Films

1990 ◽  
Vol 187 ◽  
Author(s):  
E. Ma ◽  
L.A. Clevenger ◽  
C.V. Thompson ◽  
K.N. Tu
Keyword(s):  
Electron Microscopy ◽  
Metastable Phase ◽  
Phase Evolution ◽  
Amorphous Layer ◽  
Multilayer Films ◽  
Solid State Reactions ◽  
Scanning Calorimetry ◽  
Cross Sectional ◽  
Subsequent Formation ◽  
Transmission Electron

AbstractThe growth of an amorphous Ti-Si phase and subsequent formation of crystalline silicides during solid-state reactions in Ti/a-Si multilayer films have been studied using power-compensated differential scanning calorimetry, cross-sectional transmission electron microscopy, and thin-film x-ray diffraction. By analyzing calorimetric data we have determined the activation energies for the formation of the various silicides (amorphous Ti-silicide, TiSi, C49-TiSi2, Ti5Si3) as well as their heats of formation. An amorphous silicide is the first phase to form during heating and we have measured the composition profile of this amorphous layer using scanning transimission electron microscopy. Metastable phase equilibria in the Ti-Si system are discussed in light of the thermodynamic and compositional information obtained in our experiments.

Analysis of Interface Dynamics in Solid-State Phase Transformations by In Situ Hot-Stage High-Resolution Transmission Electron Microscopy

1994 ◽  
Vol 332 ◽  
Author(s):  
James M. Howe ◽  
W. E. Benson ◽  
A. Garg ◽  
Y.-C. Chang
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Solid State ◽  
High Resolution ◽  
Phase Transformations ◽  
Interface Motion ◽  
Transmission Electron ◽  
Kinetics Of ◽  
Dynamics Of Interfaces

ABSTRACTIn situ hot-stage high-resolution transmission electron microscopy (HRTEM) provides unique capabilities for quantifying the dynamics of interfaces at the atomic level. Such information is critical for understanding the theory of interfaces and solid-state phase transformations. This paper provides a brief description of particular requirements for performing in situ hot-stage HRTEM, summarizes different types of in situ HRTEM investigations and illustrates the use of this technique to obtain quantitative data on the atomic mechanisms and kinetics of interface motion in precipitation, crystallization and martensitic reactions. Some limitations of in situ hot-stage HRTEM and future prospects of this technique are also discussed.

Solid-State Reactions in Fe/Si Multilayer Nanofilms

2014 ◽  
Vol 215 ◽  
pp. 144-149 ◽  
Author(s):  
Sergey M. Zharkov ◽  
Roman R. Altunin ◽  
Evgeny T. Moiseenko ◽  
Galina M. Zeer ◽  
Sergey N. Varnakov ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Solid State ◽  
Electron Diffraction ◽  
Solid State Reaction ◽  
Room Temperature ◽  
Solid State Reactions ◽  
Transmission Electron ◽  
Reaction Processes

Solid-state reaction processes in Fe/Si multilayer nanofilms have been studied in situ by the methods of transmission electron microscopy and electron diffraction in the process of heating from room temperature up to 900ºС at a heating rate of 8-10ºС/min. The solid-state reaction between the nanolayers of iron and silicon has been established to begin at 350-450ºС increasing with the thickness of the iron layer.

Mg–Ti–spinel formation by interfacial solid-state reaction at the TiN/MgO interface

1989 ◽  
Vol 4 (5) ◽  
pp. 1266-1271 ◽  
Author(s):  
L. Hultman ◽  
J-E. Sundgren ◽  
D. Hesse
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Solid State ◽  
Reactive Magnetron ◽  
Cross Sectional ◽  
Tin Films ◽  
Spinel Formation ◽  
Transmission Electron ◽  
Spinel Composition ◽  
Substrate Temperatures

Mg–Ti–spinel formation has been observed by cross-sectional transmission electron microscopy at the interface of TiN(100) films and MgO(100) substrates for films grown at substrate temperatures higher than 800 °C and for samples post-annealed at 850 °C. The TiN films were deposited by reactive magnetron sputtering onto cleaved (100)-oriented MgO substrates. The spinel formed 5 nm epitaxial layers along the interface with occasional (111) wedges growing into the MgO. The orientational relationships were found to be TiN(100)|spinel(100)|MgO(100) and TiN[001]|spinel[001]|MgO[001]. The spinel composition is suggested to be Mg2TiO4.

Micromechanism for Metallic-Glass Formation by Solid-State Reactions

1985 ◽  
Vol 54 (3) ◽  
pp. 197-200 ◽  
Author(s):  
H. Schröder ◽  
K. Samwer ◽  
U. Köster
Keyword(s):  
Solid State ◽  
Metallic Glass ◽  
Glass Formation ◽  
Solid State Reactions

Solid-state reaction of Ru powder in molten AlxBi1−x

1990 ◽  
Vol 5 (4) ◽  
pp. 746-753 ◽  
Author(s):  
R. W. Johnson ◽  
C. M. Garland
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Solid State ◽  
Alloy System ◽  
Reaction Cross ◽  
X Ray Diffraction ◽  
Cross Sectional ◽  
X Ray ◽  
Transmission Electron ◽  
Metal Solvent

We describe a low-temperature solid-state interdiffusion technique that allows reaction between spatially separated reacting species and its application in the Al–Ru alloy system. This technique uses a liquid-metal solvent (Bi) as a medium for the transfer of Al to the surface of Ru powder where reaction occurs with the formation of nanocrystalline AlxRu1−x product phases. X-ray diffraction measurements are used to follow the time and temperature dependence of the reaction. Cross-sectional transmission electron microscopy allows direct imaging of the growth and morphology of the AlxRu1−x product phases.

Sign in / Sign up

Export Citation Format

Share Document