In-Situ TEM Studies of Deformation Mechanisms in Nanograined Al Strengthened with Al2O3 Nanoparticles

2010 ◽  
Vol 16 (S2) ◽  
pp. 1724-1725
Author(s):  
BG Clark ◽  
JA Knapp ◽  
KM Hattar ◽  
HA Padilla ◽  
BL Boyce
Keyword(s):  
Deformation Mechanisms ◽  
In Situ Tem ◽  
Al2o3 Nanoparticles

Extended abstract of a paper presented at Microscopy and Microanalysis 2010 in Portland, Oregon, USA, August 1 – August 5, 2010.

In situ TEM Straining of Nanograined Al Films Strengthened with Al2O3 Nanoparticles

2010 ◽  
Vol 1262 ◽  
Author(s):  
Khalid Hattar ◽  
Blythe G. Clark ◽  
James A Knapp ◽  
David M Follstaedt ◽  
I. M. Robertson
Keyword(s):  
In Situ Tem ◽  
Al2o3 Nanoparticles ◽  
Particle Sizes ◽  
Free Standing ◽  
Active Deformation ◽  
Deformation And Failure ◽  
Annealing Conditions ◽  
Thermal Histories ◽  
Initial Results

AbstractGrowing interest in nanomaterials has raised many questions regarding the operating mechanisms active during the deformation and failure of nanoscale materials. To address this, a simple, effective in situ TEM straining technique was developed that provides direct detailed observations of the active deformation mechanisms at a length scale relevant to most nanomaterials. The capabilities of this new straining structure are highlighted with initial results in pulsed laser deposited (PLD) Al-Al2O3 thin films of uniform thickness. The Al-Al2O3 system was chosen for investigation, as the grain size can be tailored via deposition and annealing conditions and the active mechanisms in the binary system can be compared to previous studies in PLD Ni and evaporated Al films. PLD Al-Al2O3 free-standing films of various oxide concentrations and different thermal histories were produced and characterized in terms of average grain and particle sizes. Preliminary in situ TEM straining experiments show intergranular failure for films with 5 vol% Al2O3. Further work is in progress to explore and understand the active deformation and failure mechanisms, as well as the dependence of mechanisms on processing routes.

Deformation mechanisms at epitaxial semiconductor interfaces studied by in situ TEM

1992 ◽  
Vol 50 (1) ◽  
pp. 248-249
Author(s):  
R. Hull ◽  
J.C. Bean ◽  
F. Ross
Keyword(s):  
Strain Relaxation ◽  
High Stress ◽  
Dislocation Motion ◽  
Dislocation Nucleation ◽  
Deformation Mechanisms ◽  
Dynamic Strain ◽  
In Situ Tem ◽  
Stress Regime ◽  
Semiconductor Interfaces

We have studied deformation mechanisms at epitaxial semiconductor interfaces, primarily in the GexSi1-x/Si and InxGa1-xAs/GaAs systems, by in-situ annealing of metastably strained films in the transmission electron microscope (TEM). This allows direct, real-time, observation and recording of dynamic strain relaxation phenomena such as misfit dislocation nucleation, propagation and interaction mechanisms. This geometry also allows considerable insight into fundamental dislocation physics, as we are able, for example, to accurately quantify dislocation propagation velocities as functions of well-defined effective stresses (in the 108 - 109 pa regime)in the epitaxial layers, and to vary dislocation structure and character by varying the orientation of the epitaxial interface. Comparison with measurements of dislocation velocities in bulk semiconductors and with models of dislocation motion via kink propagation, allows extension of existing measurements and models to the thin film, high stress regime.

In situ TEM measurement of activation volume in ultrafine grained gold

Nanoscale ◽  
2020 ◽  
Vol 12 (13) ◽  
pp. 7146-7158
Author(s):  
Saurabh Gupta ◽  
Sandra Stangebye ◽  
Katherine Jungjohann ◽  
Brad Boyce ◽  
Ting Zhu ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Activation Volume ◽  
Deformation Mechanisms ◽  
In Situ Tem ◽  
Ultrafine Grained ◽  
Volume Measurements

Quantitative in situ TEM true activation volume measurements in nanoscale specimens with simultaneous observations of plastic deformation mechanisms.

In situ TEM straining of single crystal Au films on polyimide: Change of deformation mechanisms at the nanoscale

2007 ◽  
Vol 55 (16) ◽  
pp. 5558-5571 ◽  
Author(s):  
S.H. Oh ◽  
M. Legros ◽  
D. Kiener ◽  
P. Gruber ◽  
G. Dehm
Keyword(s):  
Single Crystal ◽  
Deformation Mechanisms ◽  
In Situ Tem

scholarly journals Probing Deformation Mechanisms in Ultrafine Grained Al and Au Thin Films by Quantitative In Situ TEM Deformation

2020 ◽  
Vol 26 (S2) ◽  
pp. 3188-3190
Author(s):  
Josh Kacher ◽  
Sandra Stangebye ◽  
Saurabh Gupta ◽  
Olivier Pierron
Keyword(s):  
Thin Films ◽  
Deformation Mechanisms ◽  
In Situ Tem ◽  
Ultrafine Grained ◽  
Au Thin Films

In situ TEM studies of irradiation effects for materials improvement

1991 ◽  
Vol 49 ◽  
pp. 452-453
Author(s):  
Charles W. Allen
Keyword(s):  
Nuclear Reactor ◽  
Austenitic Stainless Steels ◽  
High Energy ◽  
Point Of View ◽  
In Situ Tem ◽  
Irradiation Effects ◽  
Tem Analysis ◽  
Radiation Induced ◽  
Analytical Tools

Irradiation effects studies employing TEMs as analytical tools have been conducted for almost as many years as materials people have done TEM, motivated largely by materials needs for nuclear reactor development. Such studies have focussed on the behavior both of nuclear fuels and of materials for other reactor components which are subjected to radiation-induced degradation. Especially in the 1950s and 60s, post-irradiation TEM analysis may have been coupled to in situ (in reactor or in pile) experiments (e.g., irradiation-induced creep experiments of austenitic stainless steels). Although necessary from a technological point of view, such experiments are difficult to instrument (measure strain dynamically, e.g.) and control (temperature, e.g.) and require months or even years to perform in a nuclear reactor or in a spallation neutron source. Consequently, methods were sought for simulation of neutroninduced radiation damage of materials, the simulations employing other forms of radiation; in the case of metals and alloys, high energy electrons and high energy ions.

In situ TEM measurements of the electrical properties of interface dislocations

1992 ◽  
Vol 50 (2) ◽  
pp. 1338-1339
Author(s):  
F. M. Ross ◽  
R. Hull ◽  
D. Bahnck ◽  
J. C. Bean ◽  
L. J. Peticolas ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Electronic Device ◽  
In Situ Tem ◽  
Device Performance ◽  
Misfit Dislocations ◽  
Electrical Characteristics ◽  
Strained Layer ◽  
Transmission Electron ◽  
Interfacial Dislocations

We describe an investigation of the electrical properties of interfacial dislocations in strained layer heterostructures. We have been measuring both the structural and electrical characteristics of strained layer p-n junction diodes simultaneously in a transmission electron microscope, enabling us to correlate changes in the electrical characteristics of a device with the formation of dislocations.The presence of dislocations within an electronic device is known to degrade the device performance. This degradation is of increasing significance in the design and processing of novel strained layer devices which may require layer thicknesses above the critical thickness (hc), where it is energetically favourable for the layers to relax by the formation of misfit dislocations at the strained interfaces. In order to quantify how device performance is affected when relaxation occurs we have therefore been investigating the electrical properties of dislocations at the p-n junction in Si/GeSi diodes.

In situ TEM Studies of agglomeration of sub-nanometer Ru layers in Ru/C multilayers

1992 ◽  
Vol 50 (1) ◽  
pp. 256-257
Author(s):  
Tai D. Nguyen ◽  
Ronald Gronsky ◽  
Jeffrey B. Kortright
Keyword(s):  
Layered Structure ◽  
Driving Force ◽  
High Energy ◽  
Superior Performance ◽  
In Situ Tem ◽  
Rayleigh Instability ◽  
Practical Applications ◽  
Transmission Electron ◽  
Diffraction Patterns

Nanometer period Ru/C multilayers are one of the prime candidates for normal incident reflecting mirrors at wavelengths < 10 nm. Superior performance, which requires uniform layers and smooth interfaces, and high stability of the layered structure under thermal loadings are some of the demands in practical applications. Previous studies however show that the Ru layers in the 2 nm period Ru/C multilayer agglomerate upon moderate annealing, and the layered structure is no longer retained. This agglomeration and crystallization of the Ru layers upon annealing to form almost spherical crystallites is a result of the reduction of surface or interfacial energy from die amorphous high energy non-equilibrium state of the as-prepared sample dirough diffusive arrangements of the atoms. Proposed models for mechanism of thin film agglomeration include one analogous to Rayleigh instability, and grain boundary grooving in polycrystalline films. These models however are not necessarily appropriate to explain for the agglomeration in the sub-nanometer amorphous Ru layers in Ru/C multilayers. The Ru-C phase diagram shows a wide miscible gap, which indicates the preference of phase separation between these two materials and provides an additional driving force for agglomeration. In this paper, we study the evolution of the microstructures and layered structure via in-situ Transmission Electron Microscopy (TEM), and attempt to determine the order of occurence of agglomeration and crystallization in the Ru layers by observing the diffraction patterns.

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