Scaling laws for ion irradiation effects in iron-based superconductors

AbstractWe report on ion irradiation experiments performed on compounds belonging to the $$\hbox {BaFe}_2\hbox {As}_2$$ BaFe 2 As 2 family, each one involving the partial substitution of an atom of the parent compound (K for Ba, Co for Fe, and P for As), with an optimal composition to maximize the superconducting critical temperature $$T_c$$ T c . Employed ion beams were 3.5-MeV protons, 250-MeV Au ions, and 1.2-GeV Pb ions, but additional data from literature are also considered, thus covering a wide range of ions and energies. Microwave characterization based on the use of a coplanar waveguide resonator allowed us to investigate the irradiation-induced $$T_c$$ T c degradation, as well as the increase of normal state resistivity and London penetration depth. The damage was quantified in terms of displacements per atom (dpa). From this broad and comprehensive set of experimental data, clear scaling laws emerge, valid in the range of moderate irradiation-induced disorder (dpa up to 5 $$\times$$ × 10 $$^{-3}$$ - 3 were investigated). In these conditions, linear trends with dpa were found for all the modification rates, while a power law dependence on the ion energy was found for heavy-ion irradiation. All these scaling laws are reported and discussed throughout the paper.

Download Full-text

CONTINUOUS BACKGROUNDS IN PIXE

International Journal of PIXE ◽

10.1142/s0129083590000025 ◽

1990 ◽

Vol 01 (01) ◽

pp. 1-29 ◽

Cited By ~ 51

Author(s):

KEIZO ISHII ◽

SUSUMU MORITA

Keyword(s):

Detection Limit ◽

Heavy Ion ◽

Projectile Energy ◽

X Rays ◽

Ion Energy ◽

Electron Bremsstrahlung ◽

Wide Range ◽

Charge Dependence ◽

Rutherford Scattering ◽

Atom Collision

Continuous X rays produced by light-ion·atom collisions, which mainly form continuous backgrounds and determine the detection limit of PIXE, have been experimentally and theoretically studied, and it is shown that the experimental results over the wide range of projectile-ion energy from 0.5 MeV to 40 MeV can be well explained by three kinds of radiative process: atomic bremsstrahlung (AB), secondary-electron bremsstrahlung (SEB), and quasifree electron bremsstrahlung (QFEB). Results on the X-ray spectra, the projectile-energy dependence and the projectile-charge dependence, and on the angular distribution of these bremsstrahlungs will be summarized and the importance of AB in heavy-ion atom collision is presented. Discussions are also given on the other origins of continuous backgrounds such as the Compton scattering background, cosmic rays, the Rutherford scattering background, piling up of signals and response functions of detector, charge up effect of the target and natural backgrounds. On the basis of analyses of continuous backgrounds, the detection limit of PIXE is estimated.

Download Full-text

Effects of the Surface on Displacement Cascades Produced by Heavy-Ion Irradiation of Ni3Al and Cu3Au

MRS Proceedings ◽

10.1557/proc-439-325 ◽

1996 ◽

Vol 439 ◽

Cited By ~ 2

Author(s):

S. Müller ◽

M. L. Jenkins ◽

C. Abromeit ◽

H. Wollenberger

Keyword(s):

Ion Irradiation ◽

Incident Angle ◽

Ion Beam ◽

Heavy Ion ◽

Small Population ◽

Dislocation Loops ◽

Near Surface ◽

Ion Energy ◽

Heavy Ion Irradiation ◽

Transmission Electron

AbstractStereo transmission electron microscopy has been used to characterise the distribution in depth of disordered zones and associated dislocation loops in the ordered alloys Ni3Al and Cu3Au after heavy ion irradiation, most extensively for Ni3Al irradiated with 50 keV Ta+ ions at a temperature of 573 K. The Cu3Au specimen was irradiated with 50 keV Ni+ ions at an incident angle of 45° at a temperature of 373 K. In Ni3Al the defect yield, i.e. the probability for a disordered zone to contain a loop was found to be strongly dependent on the depth of the zone in the foil, varying from about 0.7 for near-surface zones to about 0.2 in the bulk. The sizes and shapes of disordered zones were only weakly dependent on depth, except for a small population of zones very near the surface which were strongly elongated parallel to the incident ion beam. In Cu3Au the surface had a smaller but still significant effect on the defect yield. The dependence of the tranverse disordered zone diameter d on ion energy E for Ta+ irradiation of NiA was found to follow a relationship d = k1, E1/α with k, = 2.4 ± 0.4 and α = 3.3 ± 0.4. A similar relationship with the same value of α is valid for a wide variety of incident ion/target combinations found in the literature.

Download Full-text

Effects of Oxygen Ion Irradiation on PZT Modified Ferroelectric Materials for Space Applications

International Journal of Nanotechnology and Nanomedicine ◽

10.33140/ijnn/01/01/00006 ◽

2016 ◽

Vol 1 (1) ◽

Keyword(s):

Dielectric Constant ◽

Ion Irradiation ◽

Heavy Ion ◽

Ferroelectric Material ◽

Pyroelectric Coefficient ◽

Ferroelectric Materials ◽

Dielectric Constants ◽

Space Applications ◽

Oxygen Ion ◽

Wide Range

Lead magnesium niobate-lead titanate (PMN-PT) is an important and high performance piezoelectric and pyroelectric relaxor material having wide range of applications in infrared sensor devices. Present work studies the fabrication and dielectric characteristics of PMN-PT in the bulk form. The PMN-PT bulk material was prepared in sol-gel method and subsequently irradiated with heavy ion oxygen. The materials were analyzed and determined that the relaxor ferroelectric material indicated changes in its dielectric constant and pyroelectric coefficient after irradiation. Due to the radiation fluent of 1×1016 ions/cm2 , the dielectric constant of the material increased uniformly, while its pyroelectric coefficient showed a sharp increased to the value of 5×10-9 μC/cm2 °C with increase in temperature. Its dielectric constants showed increase in values of 527 μC/cm2 °C at 50°C, 635 μC/ cm2 °C at 60°C and 748 μC/cm2 °C at 70°C. Properties such as the material impedance, admittance and modulus were investigated for changes in properties which became evident after irradiation. In this paper effect of oxygen ion irradiation on the LiTaO3 and two commercial samples BM 300 and BM 941 are also reported and analyzed. All these bulk materials were functional even after irradiation and was showing enhancement in some of the key characteristics of ferroelectric material.

Download Full-text

Ac Permeability Measurements in 770 MeV 129Xe17+ and 560 MeV 16O6+ Irradiated YBa2Cu3O7

MRS Proceedings ◽

10.1557/proc-275-213 ◽

1992 ◽

Vol 275 ◽

Author(s):

J. Bechtold ◽

X. C. Jin ◽

Y. Y. Xue ◽

I. A. Rusakova ◽

E. V. Hungerford ◽

...

Keyword(s):

Flux Pinning ◽

Ion Irradiation ◽

Magnetic Behavior ◽

Heavy Ion ◽

High Energy ◽

Critical Currents ◽

Ion Energy ◽

Heavy Ion Irradiation ◽

Strong Pinning ◽

The Difference

ABSTRACTHigh-energy heavy-ion irradiation has been shown to be effective in introducing flux-pinning defects in Y123 single crystals. Contrary to electron, low energy proton, and fast neutron irradiation, high-energy heavy-ion irradiation produces defects beneficial to flux pinning through the electronic (rather than nuclear) stopping mechanism. This type of stopping results in tubular defects many microns long that can increase the range of irreversible magnetic behavior to higher fields. In contrast, dense arrays of small defects (size < 100 Ang.) produce enhanced critical currents at low fields but do not extend the range of irreversible behavior significantly. We have used two ion-energy combinations in which the electronic stopping powers vary by nearly two orders of magnitude. The difference in stopping powers results in very different defect types, ranging from well oriented and dense (Xe) to much less well oriented and shorter (O) tubular defects. A novel analysis of the ac μ data indicates that the strong pinning introduced by the Xe irradiation breaks the vortex glass picture in favor of an individual pinning model, while O irradiation does not.

Download Full-text

Heavy-Ion Microbeams for Biological Science: Development of System and Utilization for Biological Experiments in QST-Takasaki

Quantum Beam Science ◽

10.3390/qubs3020013 ◽

2019 ◽

Vol 3 (2) ◽

pp. 13 ◽

Cited By ~ 6

Author(s):

Tomoo Funayama

Keyword(s):

Radiation Effects ◽

Cultured Cells ◽

Ion Irradiation ◽

Heavy Ion ◽

Biological Research ◽

C Elegans ◽

Beam Focusing ◽

Wide Range ◽

Vertical Beam ◽

Beam Collimation

Target irradiation of biological material with a heavy-ion microbeam is a useful means to analyze the mechanisms underlying the effects of heavy-ion irradiation on cells and individuals. At QST-Takasaki, there are two heavy-ion microbeam systems, one using beam collimation and the other beam focusing. They are installed on the vertical beam lines of the azimuthally-varying-field cyclotron of the TIARA facility for analyzing heavy-ion radiation effects on biological samples. The collimating heavy-ion microbeam system is used in a wide range of biological research not only in regard to cultured cells but also small individuals, such as silkworms, nematode C. elegans, and medaka fish. The focusing microbeam system was designed and developed to perform more precise target irradiation that cannot be achieved through collimation. This review describes recent updates of the collimating heavy ion microbeam system and the research performed using it. In addition, a brief outline of the focusing microbeam system and current development status is described.

Download Full-text

Review of Swift Heavy Ion Irradiation Effects in CeO2

Quantum Beam Science ◽

10.3390/qubs5020019 ◽

2021 ◽

Vol 5 (2) ◽

pp. 19

Author(s):

William F. Cureton ◽

Cameron L. Tracy ◽

Maik Lang

Keyword(s):

Heavy Ions ◽

Defect Formation ◽

Ion Irradiation ◽

Ion Beam ◽

Impurity Content ◽

Heavy Ion ◽

Atomic Scale ◽

Experimental Conditions ◽

Swift Heavy Ions ◽

Wide Range

Cerium dioxide (CeO2) exhibits complex behavior when irradiated with swift heavy ions. Modifications to this material originate from the production of atomic-scale defects, which accumulate and induce changes to the microstructure, chemistry, and material properties. As such, characterizing its radiation response requires a wide range of complementary characterization techniques to elucidate the defect formation and stability over multiple length scales, such as X-ray and neutron scattering, optical spectroscopy, and electron microscopy. In this article, recent experimental efforts are reviewed in order to holistically assess the current understanding and knowledge gaps regarding the underlying physical mechanisms that dictate the response of CeO2 and related materials to irradiation with swift heavy ions. The recent application of novel experimental techniques has provided additional insight into the structural and chemical behavior of irradiation-induced defects, from the local, atomic-scale arrangement to the long-range structure. However, future work must carefully account for the influence of experimental conditions, with respect to both sample properties (e.g., grain size and impurity content) and ion-beam parameters (e.g., ion mass and energy), to facilitate a more direct comparison of experimental results.

Download Full-text

Energetic Ion Irradiation as Advanced Process for Functionalization of Silicon Nanocrystals in a SiO2 Matrix

Journal of Nano Research ◽

10.4028/www.scientific.net/jnanor.18-19.241 ◽

2012 ◽

Vol 18-19 ◽

pp. 241-246 ◽

Cited By ~ 2

Author(s):

I.V. Antonova ◽

V.A. Skuratov ◽

I. Balberg

Keyword(s):

Silicon Nanocrystals ◽

Ion Irradiation ◽

Thick Layer ◽

Heavy Ion ◽

Photoluminescence Properties ◽

Ion Energy ◽

Ion Tracks ◽

Heavy Ion Irradiation ◽

Swift Heavy Ion ◽

Silicon Nanocrystallites

A physical picture of swift heavy ion irradiation effects on ensembles of silicon nanocrystallites (NCs) embedded in a dielectric SiO2matrix is given following our study of the experimental investigation of structural, electrical and photoluminescence properties of that system We found that ion irradiation can drastically change the structure of the layer by forming an ordered NC chains along the ion tracks in the 400-1000 nm thick layer. The ion energy and dose are then the main tools for functionalization of our system, from changing the size and the concentration of the NCs, to managing the optical and electrical properties.

Download Full-text

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.

Download Full-text