scholarly journals In Situ TEM Observations of Heavy Ion Damage in Gallium Arsenide

1988 ◽  
Vol 100 ◽  
Author(s):  
M. W. Bench ◽  
I. M. Robertson ◽  
M. A. Kirk
Keyword(s):  
Low Temperature ◽  
Room Temperature ◽  
National Laboratory ◽  
Argonne National Laboratory ◽  
Heavy Ion ◽  
In Situ Tem ◽  
Accelerator Facility ◽  
Transmission Electron ◽  
Ion Accelerator

ABSTRACTTransmission electron microscopy experiments have been performed to investigate the lattice damage created by heavy-ion bombardments in GaAs. These experiments have been performed in situ by using the HVEN - Ion Accelerator Facility at Argonne National Laboratory. The ion bcorbardments (50 keV Ar+ and Kr+) and the microscopy have been carried out at temperatures rangrin from 30 to 300 K. Ion fluences ranged from 2 × 1011 to 5 × 1013 ions cm−2.Direct-inpact amorphization is observed to occur in both n-type and semi-insulating GaAs irradiated to low ion doses at 30 K and room temperature. The probability of forming a visible defect is higher for low temperature irradiations than for room temperature irradiations. The amorphous zones formed at low temperature are stable to temperatures above 250 K. Post implantation annealing is seen to occur at room temperature for all samples irradiated to low doses until eventually all visible damage disappears.

The formation and recrystallization of amorphous zones produced in GaAS by ion irradiation

1988 ◽  
Vol 46 ◽  
pp. 460-461
Author(s):  
M. W. Bench ◽  
I. M. Robertson ◽  
M. A. Kirk
Keyword(s):  
Ion Irradiation ◽  
National Laboratory ◽  
Argonne National Laboratory ◽  
Heavy Ion ◽  
Accelerator Facility ◽  
Voltage Electron ◽  
Transmission Electron ◽  
Ion Accelerator ◽  
Lattice Damage ◽  
Insight Into

Transmission electron microscopy experiments have been performed to investigate the lattice damage created by heavy-ion bombardments in GaAs. These experiments were undertaken to provide additional insight into the mechanisms by which individual amorphous zones and eventually amorphous layers are created. To understand these mechanisms, the structure of the defects created as a function of material, irradiating ion, dose, dose rate, and implantation tenperature have been studied using TEM. Also, the recovery of the crystalline structure by annealing has been investigated.These experiments were performed at the High-Voltage Electron Microscope - Ion Accelerator Facility at Argonne National Laboratory. This facility consists of an HVEM which has been interfaced with two ion accelerators. This coupling, plus the availability of several specimen stages permits ion irradiations to be performed in the specimen chamber of the microscope at controlled temperatures from 10 to 1000 K.

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.

Amorphization of PLZT Material by 1.5 MeV Krypton Ion Irradiation with In Situ TEM Observation

1992 ◽  
Vol 268 ◽  
Author(s):  
L.M. Wang ◽  
A.Y. Wu ◽  
R.C. Ewing
Keyword(s):  
Single Crystals ◽  
Room Temperature ◽  
Ion Irradiation ◽  
National Laboratory ◽  
Argonne National Laboratory ◽  
Irradiation Temperature ◽  
In Situ Tem

ABSTRACTPLZT 9/65/35 single crystals were irradiated with 1.5 MeV krypton ions at 25–450°C in the HVEM-Tandem Facility at Argonne National Laboratory. In-situ TEM was performed during irradiation in order to determine the critical amorphization dose. At room temperature, the material was completely amorphized after a dose of only 1.9×1014 ions/cm2, less than one fifth of the critical amorphization dose for silicon (1×1015 ions/cm2). The critical amorphization dose for the PLZT material increased with increasing irradiation temperature. At 450°C, amorphization was not observed after a dose of 1.1×10 15ions/cm2.

Effects of krypton ion irradiation on the structure and morphology of germanium — An in situ TEM study

1990 ◽  
Vol 48 (4) ◽  
pp. 536-537
Author(s):  
L.M. Wang ◽  
R.C. Birtcher
Keyword(s):  
Ion Irradiation ◽  
Morphological Changes ◽  
Amorphous Material ◽  
National Laboratory ◽  
Argonne National Laboratory ◽  
In Situ Tem ◽  
Tandem Accelerator ◽  
Accelerator Facility ◽  
Voltage Electron

Although it was initially thought that irradiation could not further damage an amorphous material, an anomalous ion-induced morphological instability on the surface of amorphous Ge has been reported previously by several authors. In this study, the structural and morphological changes of Ge were monitored during 1.5 MeV Kr ion irradiation by in situ TEM to obtain insight into the damage evolution in ion-irradiated Ge.The in situ study was performed on the HVEM-Tandem Accelerator Facility at Argonne National Laboratory. The facility consists of a modified Kratos/AEI EM7 high voltage electron microscope (HVEM) and a 2 MV tandem ion accelerator. The samples were jet-polished polycrystalline Ge (99.99999 at. % pure) TEM discs with grain size > 5 μm in dimension. The Kr ion irradiation was carried out at room temperature, and the electron energy of the HVEM was 300 kV. According to a TRIM computer simulation, over 99% of the Kr ions penetrate through the electron transparent areas of the Ge sample, and a dose of 1×1015 Kr/cm2 created an average of ∽4 displacements per atom and an average Kr concentration of ∽12 appm in the observation region of the sample.

Electron and ion irradiation-induced dissolution of mechanical twins in the intermetalic U3Si: An in situ HVEM study

1989 ◽  
Vol 47 ◽  
pp. 652-653
Author(s):  
Charles W. Allen ◽  
Robert C. Birtcher
Keyword(s):  
Elevated Temperatures ◽  
Ion Irradiation ◽  
Ion Beam ◽  
National Laboratory ◽  
Argonne National Laboratory ◽  
Heavy Ion ◽  
High Energy ◽  
Mechanical Twinning ◽  
In Situ Experiments

The uranium silicides, including U3Si, are under study as candidate low enrichment nuclear fuels. Ion beam simulations of the in-reactor behavior of such materials are performed because a similar damage structure can be produced in hours by energetic heavy ions which requires years in actual reactor tests. This contribution treats one aspect of the microstructural behavior of U3Si under high energy electron irradiation and low dose energetic heavy ion irradiation and is based on in situ experiments, performed at the HVEM-Tandem User Facility at Argonne National Laboratory. This Facility interfaces a 2 MV Tandem ion accelerator and a 0.6 MV ion implanter to a 1.2 MeV AEI high voltage electron microscope, which allows a wide variety of in situ ion beam experiments to be performed with simultaneous irradiation and electron microscopy or diffraction.At elevated temperatures, U3Si exhibits the ordered AuCu3 structure. On cooling below 1058 K, the intermetallic transforms, evidently martensitically, to a body-centered tetragonal structure (alternatively, the structure may be described as face-centered tetragonal, which would be fcc except for a 1 pet tetragonal distortion). Mechanical twinning accompanies the transformation; however, diferences between electron diffraction patterns from twinned and non-twinned martensite plates could not be distinguished.

scholarly journals In situ environmental HRTEM discloses low temperature carbon soot oxidation by ceria–zirconia at the nanoscale

2019 ◽  
Vol 55 (27) ◽  
pp. 3876-3878 ◽  
Author(s):  
Eleonora Aneggi ◽  
Jordi Llorca ◽  
Alessandro Trovarelli ◽  
Mimoun Aouine ◽  
Philippe Vernoux
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Low Temperature ◽  
Room Temperature ◽  
Soot Oxidation ◽  
Environmental Transmission ◽  
Transmission Electron ◽  
Carbon Soot ◽  
Environmental Transmission Electron Microscopy

In situ environmental transmission electron microscopy discloses room temperature carbon soot oxidation by ceria–zirconia at the nanoscale.

In-Situ Tem Investigation During Thermal Cycling of thin Copper Films

1996 ◽  
Vol 436 ◽  
Author(s):  
R.-M. Keller ◽  
W. Sigle ◽  
S. P. Baker ◽  
O. Kraft ◽  
E. Arzt
Keyword(s):  
Grain Growth ◽  
Room Temperature ◽  
Dislocation Motion ◽  
In Situ Tem ◽  
Copper Films ◽  
Stress Evolution ◽  
Cu Films ◽  
Transmission Electron ◽  
Insight Into

AbstractIn-situ transmission electron microscopy (TEM) was performed to study grain growth and dislocation motion during temperature cycles of Cu films with and without a cap layer. In addition, the substrate curvature method was employed to determine the corresponding stresstemperature curves from room temperature up to 600°C. The results of the in-situ TEM investigations provide insight into the microstructural evolution which occurs during the stress measurements. Grain growth occurred continuously throughout the first heating cycle in both cases. The evolution of dislocation structure observed in TEM supports an explanation of the stress evolution in both capped and uncapped films in terms of dislocation effects.

scholarly journals Low-temperature plasticity of olivine revisited with in situ TEM nanomechanical testing

2016 ◽  
Vol 2 (3) ◽  
pp. e1501671 ◽  
Author(s):  
Hosni Idrissi ◽  
Caroline Bollinger ◽  
Francesca Boioli ◽  
Dominique Schryvers ◽  
Patrick Cordier
Keyword(s):  
Low Temperature ◽  
Tensile Testing ◽  
Mantle Convection ◽  
Plate Tectonics ◽  
Dislocation Dynamics ◽  
In Situ Tem ◽  
Nanomechanical Testing ◽  
Transmission Electron ◽  
Higher Temperature

The rheology of the lithospheric mantle is fundamental to understanding how mantle convection couples with plate tectonics. However, olivine rheology at lithospheric conditions is still poorly understood because experiments are difficult in this temperature range where rocks and mineral become very brittle. We combine techniques of quantitative in situ tensile testing in a transmission electron microscope and numerical modeling of dislocation dynamics to constrain the low-temperature rheology of olivine. We find that the intrinsic ductility of olivine at low temperature is significantly lower than previously reported values, which were obtained under strain-hardened conditions. Using this method, we can anchor rheological laws determined at higher temperature and can provide a better constraint on intermediate temperatures relevant for the lithosphere. More generally, we demonstrate the possibility of characterizing the mechanical properties of specimens, which can be available in the form of submillimeter-sized particles only.

Ion-Beam Amortization of Ca2La2(SiO4)6O2 Single Crystals

1992 ◽  
Vol 279 ◽  
Author(s):  
William J. Weber ◽  
Lu-Min Wang
Keyword(s):  
Electron Microscopy ◽  
Single Crystals ◽  
Structural Changes ◽  
Ion Beam ◽  
National Laboratory ◽  
Argonne National Laboratory ◽  
Annealing Process ◽  
Recoil Energy ◽  
Transmission Electron

ABSTRACTSingle crystals of Ca2La8(SiO4)6O2 were irradiated with 1.5 MeV Xe+, 1.5 MeV Kr+, 1.0 MeV Ar+ and 0.8 MeV Ne+ ions to investigate the effects of recoil-energy spectrum, temperature, and crystallographic orientation on irradiation-induced amorphization. The irradiations were carried out using the HVEM-Tandem Facility at Argonne National Laboratory. The structural changes and the ion fluence for complete amorphization in the electron transparent thickness of the specimens were determined by in situ transmission electron microscopy. The displacement dose determined for complete amorphization was approximately 0.6 dpa for the Xe+, Kr+, and Ar+ ion irradiations but increased to 1.4 dpa for the Ne+ ion irradiations, which may reflect an effect of lower recoil energies. The ion fluence for complete amorphization increased exponentially with temperature over the range from 25 to 400°C. Amorphization was not observed at 500°C. The activation energy associated with this simultaneous annealing process was estimated to be 0.13 eV, and the critical amorphization temperature was estimated to be 438°C for the 1.5 MeV Kr+ irradiations.

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