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Camara O, Mir AH, Greaves G, Donnelly SE, Hinks JA. Anomalous nucleation of crystals within amorphous germanium nanowires during thermal annealing. Nanotechnology 2021; 32:285707. [PMID: 33254162 DOI: 10.1088/1361-6528/abcef1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Accepted: 11/29/2020] [Indexed: 06/12/2023]
Abstract
In this work, germanium nanowires rendered fully amorphous via xenon ion irradiation have been annealed within a transmission electron microscope to induce crystallization. During annealing crystallites appeared in some nanowires whilst others remained fully amorphous. Remarkably, even when nucleation occurred, large sections of the nanowires remained amorphous even though the few crystallites embedded in the amorphous phase were formed at a minimum of 200 °C above the temperature for epitaxial growth and 100 °C above the temperature for random nucleation and growth in bulk germanium. Furthermore, the presence of crystallites was observed to depend on the diameter of the nanowire. Indeed, the formation of crystallites occurred at a higher annealing temperature in thin nanowires compared with thicker ones. Additionally, nanowires with a diameter above 55 nm were made entirely crystalline when the annealing was performed at the temperature normally required for crystallization in germanium (i.e. 500 °C). It is proposed that oxygen atoms hinder both the formation and the growth of crystallites. Furthermore, as crystallites must reach a minimum size to survive and grow within the amorphous nanowires, the instability of crystallites may also play a limited role for the thinnest nanowires.
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Affiliation(s)
- O Camara
- School of Computing and Engineering, University of Huddersfield, Queensgate, Huddersfield, HD1 3DH, United Kingdom
- Forschungszentrum Jülich GmbH, Institute of Energy and Climate Research-Fundamental Electrochemistry (IEK-9), D-52425 Jülich, Germany
| | - A H Mir
- School of Computing and Engineering, University of Huddersfield, Queensgate, Huddersfield, HD1 3DH, United Kingdom
| | - G Greaves
- School of Computing and Engineering, University of Huddersfield, Queensgate, Huddersfield, HD1 3DH, United Kingdom
| | - S E Donnelly
- School of Computing and Engineering, University of Huddersfield, Queensgate, Huddersfield, HD1 3DH, United Kingdom
| | - J A Hinks
- School of Computing and Engineering, University of Huddersfield, Queensgate, Huddersfield, HD1 3DH, United Kingdom
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Aradi E, Lewis-Fell J, Harrison RW, Greaves G, Mir AH, Donnelly SE, Hinks JA. Enhanced Radiation Tolerance of Tungsten Nanoparticles to He Ion Irradiation. Nanomaterials (Basel) 2018; 8:nano8121052. [PMID: 30558254 PMCID: PMC6316147 DOI: 10.3390/nano8121052] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 12/09/2018] [Accepted: 12/12/2018] [Indexed: 11/16/2022]
Abstract
Materials exposed to plasmas in magnetic confinement nuclear reactors will accumulate radiation-induced defects and energetically implanted gas atoms (from the plasma and transmutations), of which insoluble helium (He) is likely to be the most problematic. The large surface-area-to-volume ratio exhibited by nanoporous materials provides an unsaturable sink with the potential to continuously remove both point defects and He. This property enhances the possibilities for these materials to be tailored for high radiation-damage resistance. In order to explore the potential effect of this on the individual ligaments of nanoporous materials, we present results on the response of tungsten (W) nanoparticles (NPs) to 15 keV He ion irradiation. Tungsten foils and various sizes of NPs were ion irradiated concurrently and imaged in-situ via transmission electron microscopy at 750 °C. Helium bubbles were not observed in NPs with diameters less than 20 nm but did form in larger NPs and the foils. No dislocation loops or black spot damage were observed in any NPs up to 100 nm in diameter but were found to accumulate in the W foils. These results indicate that a nanoporous material, particularly one made up of ligaments with characteristic dimensions of 30 nm or less, is likely to exhibit significant resistance to He accumulation and structural damage and, therefore, be highly tolerant to radiation.
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Affiliation(s)
- E Aradi
- School of Computing and Engineering, University of Huddersfield, Queensgate, Huddersfield HD1 3DH, UK.
| | - J Lewis-Fell
- School of Computing and Engineering, University of Huddersfield, Queensgate, Huddersfield HD1 3DH, UK.
| | - R W Harrison
- School of Computing and Engineering, University of Huddersfield, Queensgate, Huddersfield HD1 3DH, UK.
- School of Mechanical, Aerospace and Civil Engineering, University of Manchester, Sackville Street, Manchester M1 3NJ, UK.
| | - G Greaves
- School of Computing and Engineering, University of Huddersfield, Queensgate, Huddersfield HD1 3DH, UK.
| | - A H Mir
- School of Computing and Engineering, University of Huddersfield, Queensgate, Huddersfield HD1 3DH, UK.
| | - S E Donnelly
- School of Computing and Engineering, University of Huddersfield, Queensgate, Huddersfield HD1 3DH, UK.
| | - J A Hinks
- School of Computing and Engineering, University of Huddersfield, Queensgate, Huddersfield HD1 3DH, UK.
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Mir AH, Hinks JA, Delaye JM, Peuget S, Donnelly SE. Xenon solubility and formation of supercritical xenon precipitates in glasses under non-equilibrium conditions. Sci Rep 2018; 8:15320. [PMID: 30333499 PMCID: PMC6192981 DOI: 10.1038/s41598-018-33556-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Accepted: 09/27/2018] [Indexed: 11/28/2022] Open
Abstract
Estimates of noble gas solubility in glasses and minerals are important to understand the origin of these gases, particularly xenon, in the atmosphere. However, technical difficulties and ambiguities in quantifying the dissolved gases introduce large uncertainties in the solubility estimates. We present here the use of transmission electron microscopy (TEM) with in-situ noble gas ion implantation as a non-equilibrium approach for noble gas solubility estimates. Using a suitable Xe equation of state and Monte-Carlo simulations of TEM images, a clear distinction between Xe filled precipitates and empty voids is made. Furthermore, implantation-induced changes in the solubility are estimated using molecular dynamics simulations. These studies allow us to evaluate the xenon solubility of irradiated and pristine silica glasses and monitor in-situ the diffusion-mediated dynamics between the precipitates and voids — otherwise impossible to capture. On exceeding the solubility limit, supercritical xenon precipitates, stable at least up to 1155 K, are formed. The results highlight the high capacity of silicates to store xenon and, predict higher solubility of radiogenic xenon due to the accompanying radiation damage.
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Affiliation(s)
- Anamul H Mir
- Electron Microscopy and Materials Analysis, School of Computing and Engineering, University of Huddersfield, Queensgate, Huddersfield, HD1 3DH, United Kingdom.
| | - J A Hinks
- Electron Microscopy and Materials Analysis, School of Computing and Engineering, University of Huddersfield, Queensgate, Huddersfield, HD1 3DH, United Kingdom
| | - Jean-Marc Delaye
- CEA, DEN, Laboratoire d'Étude des Matériaux et Procédés Actif, 30207, Bagnols-sur-Cèze, France
| | - Sylvain Peuget
- CEA, DEN, Laboratoire d'Étude des Matériaux et Procédés Actif, 30207, Bagnols-sur-Cèze, France
| | - S E Donnelly
- Electron Microscopy and Materials Analysis, School of Computing and Engineering, University of Huddersfield, Queensgate, Huddersfield, HD1 3DH, United Kingdom
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Abstract
The self-organisation of void and gas bubbles in solids into superlattices is an intriguing nanoscale phenomenon. Despite the discovery of these lattices 45 years ago, the atomistics behind the ordering mechanisms responsible for the formation of these nanostructures are yet to be fully elucidated. Here we report on the direct observation via transmission electron microscopy of the formation of bubble lattices under He ion bombardment. By careful control of the irradiation conditions, it has been possible to engineer the bubble size and spacing of the superlattice leading to important conclusions about the significance of vacancy supply in determining the physical characteristics of the system. Furthermore, no bubble lattice alignment was observed in the <111> directions pointing to a key driving mechanism for the formation of these ordered nanostructures being the two-dimensional diffusion of self-interstitial atoms.
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Affiliation(s)
- R W Harrison
- School of Computing and Engineering, University of Huddersfield, Huddersfield, HD1 3DH, UK.
| | - G Greaves
- School of Computing and Engineering, University of Huddersfield, Huddersfield, HD1 3DH, UK
| | - J A Hinks
- School of Computing and Engineering, University of Huddersfield, Huddersfield, HD1 3DH, UK
| | - S E Donnelly
- School of Computing and Engineering, University of Huddersfield, Huddersfield, HD1 3DH, UK
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Pan CT, Hinks JA, Ramasse QM, Greaves G, Bangert U, Donnelly SE, Haigh SJ. In-situ observation and atomic resolution imaging of the ion irradiation induced amorphisation of graphene. Sci Rep 2014; 4:6334. [PMID: 25284688 PMCID: PMC4185388 DOI: 10.1038/srep06334] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Accepted: 08/20/2014] [Indexed: 12/03/2022] Open
Abstract
Ion irradiation has been observed to induce a macroscopic flattening and in-plane shrinkage of graphene sheets without a complete loss of crystallinity. Electron diffraction studies performed during simultaneous in-situ ion irradiation have allowed identification of the fluence at which the graphene sheet loses long-range order. This approach has facilitated complementary ex-situ investigations, allowing the first atomic resolution scanning transmission electron microscopy images of ion-irradiation induced graphene defect structures together with quantitative analysis of defect densities using Raman spectroscopy.
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Affiliation(s)
- C-T Pan
- 1] School of Materials, University of Manchester, Material Science Centre, Grosvenor Street, Manchester, M13 9PL, United Kingdom [2] School of Physics and Astronomy, University of Manchester, Manchester, Oxford Road, M13 9PL, United Kingdom
| | - J A Hinks
- School of Computing and Engineering, University of Huddersfield, HD1 3DH, United Kingdom
| | - Q M Ramasse
- SuperSTEM Laboratory, STFC Daresbury Campus, Keckwick Lane, Daresbury WA4 4AD, United Kingdom
| | - G Greaves
- School of Computing and Engineering, University of Huddersfield, HD1 3DH, United Kingdom
| | - U Bangert
- 1] School of Materials, University of Manchester, Material Science Centre, Grosvenor Street, Manchester, M13 9PL, United Kingdom [2]
| | - S E Donnelly
- School of Computing and Engineering, University of Huddersfield, HD1 3DH, United Kingdom
| | - S J Haigh
- School of Materials, University of Manchester, Material Science Centre, Grosvenor Street, Manchester, M13 9PL, United Kingdom
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El-Atwani O, Hinks JA, Greaves G, Gonderman S, Qiu T, Efe M, Allain JP. In-situ TEM observation of the response of ultrafine- and nanocrystalline-grained tungsten to extreme irradiation environments. Sci Rep 2014; 4:4716. [PMID: 24796578 PMCID: PMC4010930 DOI: 10.1038/srep04716] [Citation(s) in RCA: 113] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Accepted: 03/12/2014] [Indexed: 11/08/2022] Open
Abstract
The accumulation of defects, and in particular He bubbles, can have significant implications for the performance of materials exposed to the plasma in magnetic-confinement nuclear fusion reactors. Some of the most promising candidates for deployment into such environments are nanocrystalline materials as the engineering of grain boundary density offers the possibility of tailoring their radiation resistance properties. In order to investigate the microstructural evolution of ultrafine- and nanocrystalline-grained tungsten under conditions similar to those in a reactor, a transmission electron microscopy study with in situ 2 keV He(+) ion irradiation at 950 °C has been completed. A dynamic and complex evolution in the microstructure was observed including the formation of defect clusters, dislocations and bubbles. Nanocrystalline grains with dimensions less than around 60 nm demonstrated lower bubble density and greater bubble size than larger nanocrystalline (60-100 nm) and ultrafine (100-500 nm) grains. In grains over 100 nm, uniform distributions of bubbles and defects were formed. At higher fluences, large faceted bubbles were observed on the grain boundaries, especially on those of nanocrystalline grains, indicating the important role grain boundaries can play in trapping He and thus in giving rise to the enhanced radiation tolerance of nanocrystalline materials.
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Affiliation(s)
- O. El-Atwani
- School of Nuclear Engineering, Purdue University, West Lafayette, IN 47906
- School of Materials Engineering, Purdue University, West Lafayette, IN 47906
- Birck Nanotechnology Center, West Lafayette, IN 47906
| | - J. A. Hinks
- School of Computing and Engineering, University of Huddersfield, HD1 3DH, United Kingdom
| | - G. Greaves
- School of Computing and Engineering, University of Huddersfield, HD1 3DH, United Kingdom
| | - S. Gonderman
- School of Nuclear Engineering, Purdue University, West Lafayette, IN 47906
| | - T. Qiu
- School of Materials Engineering, Purdue University, West Lafayette, IN 47906
| | - M. Efe
- Center for Materials Processing and Tribology, Purdue University, West Lafayette, IN, USA
- Current address: Department of Metallurgical and Materials Engineering, Middle East Technical University, Ankara, Turkey
| | - J. P. Allain
- School of Nuclear Engineering, Purdue University, West Lafayette, IN 47906
- School of Materials Engineering, Purdue University, West Lafayette, IN 47906
- Birck Nanotechnology Center, West Lafayette, IN 47906
- Current address: Department of Nuclear, Plasma and Radiological Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801
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Greaves G, Hinks JA, Busby P, Mellors NJ, Ilinov A, Kuronen A, Nordlund K, Donnelly SE. Enhanced sputtering yields from single-ion impacts on gold nanorods. Phys Rev Lett 2013; 111:065504. [PMID: 23971585 DOI: 10.1103/physrevlett.111.065504] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2013] [Revised: 05/12/2013] [Indexed: 05/07/2023]
Abstract
Sputtering yields, enhanced by more than an order of magnitude, have been observed for 80 keV Xe ion irradiation of monocrystalline Au nanorods. Yields are in the range 100-1900 atoms/ion compared with values for a flat surface of ≈50. This enhancement results in part from the proximity of collision cascades and ensuing thermal spikes to the nanorod surfaces. Molecular dynamic modeling reveals that the range of incident angles occurring for irradiation of nanorods and the larger number of atoms in "explosively ejected" atomic clusters make a significant contribution to the enhanced yield.
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Affiliation(s)
- G Greaves
- School of Computing and Engineering, University of Huddersfield, Huddersfield HD1 3DH, United Kingdom
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Hinks JA, Jones AN, Theodosiou A, van den Berg JA, Donnelly SE. Transmission Electron Microscopy Study of Graphite underin situIon Irradiation. ACTA ACUST UNITED AC 2012. [DOI: 10.1088/1742-6596/371/1/012046] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Hinks JA, Roe M, Ho JCY, Watts FZ, Phelan J, McAllister M, Pearl LH. Expression, purification and preliminary X-ray analysis of the BRCT domain from Rhp9/Crb2. Acta Crystallogr D Biol Crystallogr 2003; 59:1230-3. [PMID: 12832769 DOI: 10.1107/s0907444903007054] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2003] [Accepted: 03/26/2003] [Indexed: 11/10/2022]
Abstract
The BRCT domain from Rhp9 (a Schizosaccharomyces pombe DNA-damage checkpoint protein) has been expressed, purified and crystallized. Overexpression in bacterial cells was achieved by minimizing aeration during host cell growth. A robotic screen was used to determine the solubility parameters; concentration of the protein was achieved by exploiting this information. Single crystals suitable for X-ray analysis were obtained in two forms by vapour diffusion (trigonal, unit-cell parameters a = b = 228.04, c = 70.42 A, and tetragonal, P4/m Laue group symmetry, unit-cell parameters a = b = 72.3, c = 91.1 A).
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Affiliation(s)
- J A Hinks
- CR-UK DNA Repair Enzyme Group, Institute of Cancer Research, 237 Fulham Road, South Kensington, London SW3 6JB, England
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