Special Issue "Neutron Diffractometers for Single Crystals and Powders"

A special issue of Crystals (ISSN 2073-4352). This special issue belongs to the section "Crystalline Materials".

Deadline for manuscript submissions: closed (31 July 2018)

Special Issue Editors

Guest Editor
Dr. A.M. Balagurov

Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Joliot-Curie 6,Dubna, Russia
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Interests: neutron diffraction, atomic structures, phase transitions, TOF technique
Guest Editor
Dr. A.G. Goukassov

Laboratoire Léon Brillouin, CEA Saclay, bât.563, 91191 Gif-sur-Yvette Cedex, France
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Interests: neutron diffraction, magnetic diffraction, magnetic sructures
Guest Editor
Dr. T.C. Hansen

Institut Laue-Langevin, 71 avenue des Martyrs, 38000 Grenoble, France
Website | E-Mail
Interests: neutron powder diffraction, in situ diffraction, oxides, ice and hydrates

Special Issue Information

Dear Colleagues,

Neutron diffraction has long established itself as an extremely effective tool for studying atomic and magnetic structures, as well as the microstructure of crystalline materials—the knowledge of which is the basis for understanding their physical and engineering properties. Accordingly, at least one (and more often several) neutron diffractometers can be found at any research neutron source. Unlike X-ray diffractometers, the design of each neutron diffractometer is more or less original, and is dependent on the type of neutron source, and on the specific diffraction problem for which it is aimed.

At present, neutron experiments are conducted on two types of research sources: steady-state nuclear reactors (e.g. HFR of ILL (France) producing the most intense continuous flux in the world), and pulsed sources based on proton accelerators and a heavy metal target (e.g. ISIS at RAL (UK) and most recent ones SNS (USA) and J-PARC (Japan)). In addition, active work is carried out on two non-standard neutron sources: SINQ (PSI, Switzerland), which is based on proton accelerators, but steady-state; and IBR-2 (JINR, Russia), which is a nuclear reactor but pulsed. It should also be noted that in the nearest future the European Spallation Source (under construction) will operate in Lund, Sweden. Its high blilliance and long pulse structure shall open new possibilities in neutron diffraction.

The variety of structural and materials science problems solved with neutron diffraction is very large. The need to optimize the parameters for solving specific problems has determined the variety of constructions of neutron diffractometers. Somewhat arbitrary, it is possible to identify a dozen instrument types differing in their main characteristics (resolution, intensity, d-spacing range) and in the design of the detector system. For instance, the construction of diffractometers at steady-state and at pulsed sources, as well as for single crystals and powders differ radically. Among the latter, one can distinguish between high-resolution and high-intensity instruments, between diffractometers for texture analysis and for measuring internal stresses, etc.

Obviously, for the successful solution of a specific problem, a correct choice of diffractometer is necessary, and we hope that current and potential users of neutron diffraction will be correctly guided by this Special Issue of the journal.

Dr. A.M. Balagurov
Dr. A.G. Goukassov
Dr. T.C. Hansen
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Crystals is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1200 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • Neutron diffractometers
  • Atomic structure
  • Magnetic structure
  • Crystal microstructure

Published Papers (5 papers)

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Research

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Open AccessArticle Tracing Phase Transformation and Lattice Evolution in a TRIP Sheet Steel under High-Temperature Annealing by Real-Time In Situ Neutron Diffraction
Crystals 2018, 8(9), 360; https://doi.org/10.3390/cryst8090360
Received: 31 July 2018 / Revised: 22 August 2018 / Accepted: 6 September 2018 / Published: 11 September 2018
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Abstract
Real-time in situ neutron diffraction was used to characterize the crystal structure evolution in a transformation-induced plasticity (TRIP) sheet steel during annealing up to 1000 °C and then cooling to 60 °C. Based on the results of full-pattern Rietveld refinement, critical temperature regions
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Real-time in situ neutron diffraction was used to characterize the crystal structure evolution in a transformation-induced plasticity (TRIP) sheet steel during annealing up to 1000 °C and then cooling to 60 °C. Based on the results of full-pattern Rietveld refinement, critical temperature regions were determined in which the transformations of retained austenite to ferrite and ferrite to high-temperature austenite during heating and the transformation of austenite to ferrite during cooling occurred, respectively. The phase-specific lattice variation with temperature was further analyzed to comprehensively understand the role of carbon diffusion in accordance with phase transformation, which also shed light on the determination of internal stress in retained austenite. These results prove the technique of real-time in situ neutron diffraction as a powerful tool for heat treatment design of novel metallic materials. Full article
(This article belongs to the Special Issue Neutron Diffractometers for Single Crystals and Powders)
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Open AccessArticle Bending Behavior of a Wrought Magnesium Alloy Investigated by the In Situ Pinhole Neutron Diffraction Method
Crystals 2018, 8(9), 348; https://doi.org/10.3390/cryst8090348
Received: 31 July 2018 / Revised: 26 August 2018 / Accepted: 27 August 2018 / Published: 30 August 2018
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Abstract
The tensile twinning and detwinning behaviors of a wrought magnesium alloy have been investigated during in situ four-point bending using the state-of-the-art high spatial resolution pinhole neutron diffraction (PIND) method. The PIND method allowed us to resolve the tensile twinning/detwinning and lattice strain
[...] Read more.
The tensile twinning and detwinning behaviors of a wrought magnesium alloy have been investigated during in situ four-point bending using the state-of-the-art high spatial resolution pinhole neutron diffraction (PIND) method. The PIND method allowed us to resolve the tensile twinning/detwinning and lattice strain distributions across the bending sample during a loading-unloading sequence with a 0.5 mm step size. It was found that the extensive tensile twinning and detwinning occurred near the compression surface, while no tensile twinning behavior was observed in the middle layer and tension side of the bending sample. During the bending, the neutral plane shifted from the compression side to the tension side. Compared with the traditional neutron diffraction mapping method, the PIND method provides more detailed information inside the bending sample due to a higher spatial resolution. Full article
(This article belongs to the Special Issue Neutron Diffractometers for Single Crystals and Powders)
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Open AccessArticle The DN-6 Neutron Diffractometer for High-Pressure Research at Half a Megabar Scale
Crystals 2018, 8(8), 331; https://doi.org/10.3390/cryst8080331
Received: 18 July 2018 / Revised: 15 August 2018 / Accepted: 18 August 2018 / Published: 20 August 2018
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Abstract
A neutron diffractometer DN-6 at the IBR-2 high-flux reactor is used for the studies of crystal and magnetic structure of powder materials under high pressure in a wide temperature range. The high neutron flux on the sample due to a parabolic focusing section
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A neutron diffractometer DN-6 at the IBR-2 high-flux reactor is used for the studies of crystal and magnetic structure of powder materials under high pressure in a wide temperature range. The high neutron flux on the sample due to a parabolic focusing section of a neutron guide and wide solid angle of the detector system enables neutron diffraction experiments with extraordinarily small volumes (about 0.01 mm3) of studied samples. The diffractometer is equipped with high-pressure cells with sapphire and diamond anvils, which allow pressures of up to 50 GPa to be reached. The technical design, main parameters and current capabilities of the diffractometer are described. A brief overview of recently obtained results is given. Full article
(This article belongs to the Special Issue Neutron Diffractometers for Single Crystals and Powders)
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Open AccessArticle Neutron RTOF Stress Diffractometer FSD at the IBR-2 Pulsed Reactor
Crystals 2018, 8(8), 318; https://doi.org/10.3390/cryst8080318
Received: 18 July 2018 / Revised: 4 August 2018 / Accepted: 6 August 2018 / Published: 9 August 2018
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Abstract
The diffraction of thermal neutrons is a powerful tool for investigations of residual stresses in various structural materials and bulk industrial products due to the non-destructive character of the method and high penetration depth of neutrons. Therefore, for conducting experiments in this research
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The diffraction of thermal neutrons is a powerful tool for investigations of residual stresses in various structural materials and bulk industrial products due to the non-destructive character of the method and high penetration depth of neutrons. Therefore, for conducting experiments in this research field, the neutron Fourier stress diffractometer FSD has been constructed at the IBR-2 pulsed reactor in FLNP JINR (Dubna, Russia). Using a special correlation technique at the long-pulse neutron source, a high resolution level of the instrument has been achieved (Δd/d ≈ 2 ÷ 4 × 10−3) over a wide range of interplanar spacing dhkl at a relatively short flight distance between the chopper and sample position (L = 5.55 m). The FSD design satisfies the requirements of a high luminosity, high resolution, and specific sample environment. In this paper, the current status of the FSD diffractometer is reported and examples of performed experiments are given. Full article
(This article belongs to the Special Issue Neutron Diffractometers for Single Crystals and Powders)
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Review

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Open AccessReview The Neutron Macromolecular Crystallography Instruments at Oak Ridge National Laboratory: Advances, Challenges, and Opportunities
Crystals 2018, 8(10), 388; https://doi.org/10.3390/cryst8100388
Received: 25 September 2018 / Revised: 3 October 2018 / Accepted: 5 October 2018 / Published: 11 October 2018
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Abstract
The IMAGINE and MaNDi instruments, located at Oak Ridge National Laboratory High Flux Isotope Reactor and Spallation Neutron Source, respectively, are powerful tools for determining the positions of hydrogen atoms in biological macromolecules and their ligands, orienting water molecules, and for differentiating chemical
[...] Read more.
The IMAGINE and MaNDi instruments, located at Oak Ridge National Laboratory High Flux Isotope Reactor and Spallation Neutron Source, respectively, are powerful tools for determining the positions of hydrogen atoms in biological macromolecules and their ligands, orienting water molecules, and for differentiating chemical states in macromolecular structures. The possibility to model hydrogen and deuterium atoms in neutron structures arises from the strong interaction of neutrons with the nuclei of these isotopes. Positions can be unambiguously assigned from diffraction studies at the 1.5–2.5 Å resolutions, which are typical for protein crystals. Neutrons have the additional benefit for structural biology of not inducing radiation damage to protein crystals, which can be critical in the study of metalloproteins. Here we review the specifications of the IMAGINE and MaNDi beamlines and illustrate their complementarity. IMAGINE is suitable for crystals with unit cell edges up to 150 Å using a quasi-Laue technique, whereas MaNDi provides neutron crystallography resources for large unit cell samples with unit cell edges up to 300 Å using the time of flight (TOF) Laue technique. The microbial culture and crystal growth facilities which support the IMAGINE and MaNDi user programs are also described. Full article
(This article belongs to the Special Issue Neutron Diffractometers for Single Crystals and Powders)
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