HREM study of phase transformation induced by ion irradiation in Al-Cu-Co-Ge single decagonal quasicrystal

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100166075 ◽

1996 ◽

Vol 54 ◽

pp. 722-723

Author(s):

L.F. Chen ◽

L.M. Wang ◽

R.C. Ewing

Keyword(s):

Phase Transformation ◽

Ion Irradiation ◽

National Laboratory ◽

Research Field ◽

In Situ Tem ◽

Decagonal Quasicrystal ◽

University Of New Mexico ◽

Fundamental Understanding ◽

The University

Irradiation-induced phase transformation in crystals has been an interesting research field for the past twenty years. Since the discovery of quasicrystals in Al-based alloys, there have been some reports on irradiation-induced phase transformation in quasicrystals by in situ TEM observations. However, detailed study on phase transformation in quasicrystals under ion irradiation at atomic level using HREM is necessary for the fundamental understanding of the process. In this paper, we report the results from a systematic HREM study on phase transformation induced by ion irradiation in Al-Cu-Co-Ge single decagonal quasicrystal (31.4 wt.% Cu, 21.8 wt.% Co and 5.4 wt.% Ge).The TEM specimens of single decagonal quasicrystal were prepared perpendicular to the tenfold axis. The transformation in single quasicrystal was studied by in situ TEM during 1.5 MeV Xe+ ion irradiation at room temperature using the HVEM-Tandem Facility at Argon National Laboratory and examined in detail by HREM using a JEM2010 microscope at the University of New Mexico after the irradiation.

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Crystallization of nano-size thallous oxide during ion irradiation of Tl-Ba-Ca-Cu-O high-temperature superconductors

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100137446 ◽

1995 ◽

Vol 53 ◽

pp. 214-215

Author(s):

P. P. Newcomer ◽

L. M. Wang ◽

M. L. Miller ◽

R. C. Ewing

Keyword(s):

High Temperature ◽

Ion Irradiation ◽

Ion Beam ◽

High Temperature Superconductors ◽

National Laboratory ◽

Argonne National Laboratory ◽

Planetary Science ◽

University Of New Mexico ◽

The University ◽

Nano Size

The Tl-Ba-Ca-Cu-O class of type-II high temperature superconductors (HTS) have Tc's as high as 125K. Although they have good critical current values, when a field is applied the weak pinning and consequent flow of magnetic vortices are a major impediment to the usefulness of these materials. Ion irradiation has been shown to enhance the pinning. High quality single crystals, as determined with x-ray precession and HRTEM, with sharp HTS Meissner signals, were irradiated with 1.5 MeV Kr+ and Xe+ ions using the HVEM-Tandem facility at Argonne National Laboratory. Ion beam microstructural modification was studied in-situ using electron diffraction and after irradiation using HRTEM and nano-beam EDS on Tl-1212 and Tl-2212 (numbers designate the stoichiometry Tl-Ba- Ca-Cu-O) single-crystal HTS. After irradiation, microstructure was studied using the JEOL 2010 in the Earth and Planetary Science Department at the University of New Mexico in order to characterize the resulting irradiation-induced nano-size precipitates.

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

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100175806 ◽

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.

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Organocatalyzed C–C Ring Construction: The Carreira Synthesis of (+)-Crotogoudin

Organic Synthesis ◽

10.1093/oso/9780190646165.003.0069 ◽

2017 ◽

Author(s):

Douglass F. Taber

Keyword(s):

National Laboratory ◽

Unsaturated Aldehyde ◽

Materia Medica ◽

University Of New Mexico ◽

Effective Strategies ◽

Ester Enolate ◽

Robinson Annulation ◽

The University ◽

Peptide Catalyst

Kazuaki Kudo of the University of Tokyo developed (Org. Lett. 2013, 15, 4964) a peptide catalyst for the enantioselective construction of 3 by the addition of 2 to 1. Thorsten Bach of the Technische Universität München devised (Science 2013, 342, 840; J. Am. Chem. Soc. 2013, 135, 14948) a Lewis acid organocatalyst for the photocyclization of 4 to 5. Albert Moyano of the Universitat de Barcelona effected (Eur. J. Org. Chem. 2013, 3103) enantioselective conjugate addition of 7 to 6 to give the cyclopentane 8. Daniel Romo of Texas A&M optimized (Nature Chem. 2013, 5, 1049) the addition of 9 to 10 to give the β-lactone 11. Kamal Kumar and Herbert Waldmann of the Technische Universität Dortmund found (Angew. Chem. Int. Ed. 2013, 52, 9576) that the addition of 12 to 13 followed by Bayer–Villiger oxidation and deacylation delivered 14 in high ee. David W. Lupton of Monash University opened (Angew. Chem. Int. Ed. 2013, 52, 9149) the cyclopropane of 15 in situ, leading to an ester enolate that added to 16 to give 17. Jeffrey S. Johnson of the University of North Carolina used (Chem. Sci. 2013, 4, 2828) an organocatalyst to mediate the addition of the prochiral 18 to 19, leading to 20. M. Belén Cid of the Universidad Autónoma de Madrid added (J. Org. Chem. 2013, 78, 10737) the nitroalkane 22 to the unsaturated aldehyde 21, leading, after intramolecular Julia-Kocienski addition, to the cyclohexene 23. Additions that proceed in high ee with cyclopentenone and cyclohexenone are often not as selective with cycloheptenone 24. Wei Wang of the University of New Mexico and Wenhu Duan of the Shanghai Institute of Materia Medica observed (Tetrahedron Lett. 2013, 54, 3791) that addition of nitromethane and of nitroethane to 24 were both highly effective. Strategies have been developed for applying organocatalysis to the assembly of polycarbacyclic ring systems. Sanzhong Luo of the Beijing National Laboratory for Molecule Sciences uncovered (Synthesis 2013, 45, 1939) a simple amine that efficiently catalyzed the Robinson annulation of 26 with 27 to give 28.

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

MRS Proceedings ◽

10.1557/proc-268-343 ◽

1992 ◽

Vol 268 ◽

Cited By ~ 6

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.

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

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100175818 ◽

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.

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

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100155232 ◽

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.

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The Effect of Flux on Ion Irradiation-Induced Precipitation in AISI-316L: An In-Situ TEM Study

SSRN Electronic Journal ◽

10.2139/ssrn.3568079 ◽

2020 ◽

Author(s):

Ítalo M. Oyarzabal ◽

Matheus A. Tunes ◽

Osmane Camara ◽

Emily Aradi ◽

Anamul H. Mir ◽

...

Keyword(s):

Ion Irradiation ◽

In Situ Tem ◽

Aisi 316L

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Ion Irradiation of Ternary Pyrochlores

MRS Proceedings ◽

10.1557/proc-1122-o08-03 ◽

2008 ◽

Vol 1122 ◽

Author(s):

Karl R. Whittle ◽

Katherine L. Smith ◽

Mark G. Blackford ◽

Simon A.T. Redfern ◽

Elizabeth J. Harvey ◽

...

Keyword(s):

Ion Irradiation ◽

National Laboratory ◽

Argonne National Laboratory ◽

Structural Disorder ◽

Critical Temperatures ◽

High Doses

AbstractSynthetic pyrochlore samples Y2Ti2-xSnxO7 (x=0.4, 0.8, 1.2, 1.6), Nd2Zr2O7, Nd2Zr1.2Ti0.8O7, and La1.6Y0.4Hf2O7, were irradiated in-situ using the IVEM-TANDEM microscope facility at the Argonne National Laboratory. The critical temperatures for amorphisation have revealed a dramatic increase in tolerance with increasing Sn content for the Y2Ti2-xSnxO7 series. This change has also found to be linear with increasing Sn content. Nd2Zr1.2Ti0.8O7 and La1.6Y0.4Hf2O7 were both found to amorphise, while Nd2Zr2O7 was found to be stable to high doses (2.5×10^15 ions cm-2). The observed results are presented with respect to previously published results for irradiation stability predictions and structural disorder.

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