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 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.

In Situ TEM Analysis of Organic–Inorganic Metal-Halide Perovskite Solar Cells under Electrical Bias

Nano Letters ◽  
2016 ◽  
Vol 16 (11) ◽  
pp. 7013-7018 ◽  
Author(s):  
Quentin Jeangros ◽  
Martial Duchamp ◽  
Jérémie Werner ◽  
Maximilian Kruth ◽  
Rafal E. Dunin-Borkowski ◽  
...  
Keyword(s):  
Solar Cells ◽  
Perovskite Solar Cells ◽  
Metal Halide ◽  
In Situ Tem ◽  
Tem Analysis ◽  
Metal Halide Perovskite ◽  
Halide Perovskite ◽  
Electrical Bias

HREM In-Situ Studies of Electron Irradiation Effects in Oxides

1988 ◽  
Vol 100 ◽  
Author(s):  
D. E. Luzzi ◽  
L. D. Marks ◽  
M. I. Buckett ◽  
J. W. Strane ◽  
B. W. Wessels ◽  
...  
Keyword(s):  
Electron Irradiation ◽  
Point Of View ◽  
Irradiation Damage ◽  
Original Material ◽  
Irradiation Effects ◽  
Resolution Electron ◽  
Wide Range ◽  
Electronic Irradiation ◽  
High Resolution Electron Microscope

ABSTRACTHigh resolution electron microscope (HREM) studies provide the ability to study desorption and sputtering from the perspective of the analysis of the resultant materials, their structure, composition and atomic registry (orientation with respect to the original,material and the irradiation). This is a neglected facet of surface irradiation effects research, yet it is the most important from the technological point of view. In the current study, surface electron irradiation processes in oxides were studied in-situ in a Hitachi H-9000 HREM operated at incident electron energies of 100–300 keV. It was found that a wide range of processes occur in the HREM which are dependent on the energy and flux of the incident electrons and on the material properties. Both ballistic and electronic irradiation damage was observed and the material responses included surface sputtering, amorphisation, chemical disordering, desorption of O and metal surface layer creation, surface roughening and bulk defect creation.

In Situ TEM Analysis of Facet Motion in Gold Σ=3 {112} Boundaries

2001 ◽  
Vol 7 (S2) ◽  
pp. 324-325
Author(s):  
D.L. Medlin
Keyword(s):  
Thin Films ◽  
Grain Boundary ◽  
Microstructural Evolution ◽  
Experimental Studies ◽  
In Situ Tem ◽  
Tem Analysis ◽  
Computational Approaches ◽  
Boundary Properties ◽  
Boundary Curvature

Interfacial anisotropy complicates the prediction of microstructural evolution, particularly ir extreme cases for which the presence of facets and corners prevents the application of classical notions of grain-boundary curvature. Although there has been much effort at incorporating anisotropic grain-boundary properties, including faceted geometries, into computational approaches for microstructural evolution, at present our mechanistic understanding of the behavior of facets anc their junctions remains limited. In this presentation, we investigate the development of faceted boundaries between Σ=3 <111> oriented grains in epitaxially deposited gold thin films. This system is well suited tc experimental studies of facet evolution since the crystallography and structure of the boundaries is already well understood. It is well known that “double-positioning” of epitaxially aligned <111> grains on a surface of three-fold or six-fold symmetry results in a microstructure composed of grains in two twin-related (Σ=3) variants that are separated by facets running vertically through the film and forming 120 degree corners [1,2].

Radiation-induced disordering and amorphization—An in situ HVEM study of uranium silicide with comparison to natural processes in zirconolite

1990 ◽  
Vol 48 (4) ◽  
pp. 534-535
Author(s):  
R. C. Birtcher ◽  
L. M. Wang ◽  
C. W. Allen ◽  
R. C. Ewing
Keyword(s):  
Electron Irradiation ◽  
Ion Irradiation ◽  
Ion Beam ◽  
National Laboratory ◽  
Argonne National Laboratory ◽  
Heavy Ion ◽  
High Energy ◽  
In Situ Tem ◽  
In Situ Experiments

We present here results of in situ TEM diffraction observations of the response of U3Si and U3Si2 when subjected to 1 MeV electron irradiation or to 1.5 MeV Kr ion irradiation, and observations of damage occuring in natural zirconolite. High energy electron irradiation or energetic heavy ion irradiation were performed in situ at the HVEM-Tandem User Facility at Argonne National Laboratory. In this Facility, a 2 MV Tandem ion accelerator and a 0.6 MV ion implanter have been interfaced to a 1.2 MeV AEI high voltage electron microscope. This allows a wide variety of in situ experiments to be performed with simultaneous ion irradiation and conventional transmission electron microscopy. During the electron irradiation, the electron beam was focused to a diameter of about 2 μ.m at the specimen thin area. The ion beam was approximately 2 mm in diameter and was uniform over the entire specimen. With the specimen mounted in a heating holder, the temperature increase indicated by the furnace thermocouple during the ion irradiation was typically 8 °K.

In Situ Tem Observation of Radiation Induced Amorphizatton of Crystals with Apatite Structure

2017 ◽  
pp. 243-249 ◽  
Author(s):  
L.M. Wang ◽  
M. Cameron ◽  
W.J. Weber ◽  
K.D. Crowley ◽  
R.C. Ewing*
Keyword(s):  
In Situ Tem ◽  
Apatite Structure ◽  
Radiation Induced

scholarly journals Electron Beam Effects during In-Situ Annealing of Self-Ion Irradiated Nanocrystalline Nickel

2015 ◽  
Vol 1809 ◽  
pp. 13-18 ◽  
Author(s):  
Brittany Muntifering ◽  
Rémi Dingreville ◽  
Khalid Hattar ◽  
Jianmin Qu
Keyword(s):  
Electron Beam ◽  
Nuclear Reactor ◽  
Ion Irradiation ◽  
Nanocrystalline Nickel ◽  
Transmission Electron ◽  
Radiation Induced ◽  
Reactor Materials ◽  
Diffraction Patterns ◽  
Underlying Mechanisms

ABSTRACTTransmission electron microscopy (TEM) is a valuable methodology for investigating radiation-induced microstructural changes and elucidating the underlying mechanisms involved in the aging and degradation of nuclear reactor materials. However, the use of electrons for imaging may result in several inadvertent effects that can potentially change the microstructure and mechanisms active in the material being investigated. In this study, in situ TEM characterization is performed on nanocrystalline nickel samples under self-ion irradiation and post irradiation annealing. During annealing, voids are formed around 200 °C only in the area illuminated by the electron beam. Based on diffraction patterns analyses, it is hypothesized that the electron beam enhanced the growth of a NiO layer resulting in a decrease of vacancy mobility during annealing. The electron beam used to investigate self-ion irradiation ultimately significantly affected the type of defects formed and the final defect microstructure.

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