Magnetic nanoparticles for space applications

ABSTRACTRadiation resistant ferrite materials have potential applications in space station. Mg-Mn spinel ferrite was choosen for this study because of its radiation resistance and potential for use as an insulator in radiation environments. The radiation damage expected in these environments can be quickly and conveniently simulated using ion irradiation. The results of swift heavy ion irradiation induced modifications in the magnetization behavior of the Mg-Mn ferrite nanoparticles have been investigated using 100 MeV Ni8+ ion irradiation. To ensure the singlephase spinel structure of the system powder x-ray diffraction patterns has been performed. The powder samples were irradiated at three different fluences in the range 1×1012-5×1013 ions/cm2. Isothermal dc magnetization studies have been performed using SQUID and vibration sample magnetometer (VSM) on the pristine as well as on the irradiated samples at 20 K and 300 K. With irradiation saturation magnetization remains almost constant with ions irradiation. The coercivity values of the materials decreased about 5% with the fluence 1×1013 ions/cm2 as compare to the pristine nanoparticles. The results have been explained on the basis of the existence of surface defects produced by swift heavy ions, which generate orientational disorder of surface spins. The behavior of saturation magnetization with irradiations makes these nanoparticles suitable for memory devices in the space research.

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Comparison of short-range order in irradiated dysprosium titanates

npj Materials Degradation ◽

10.1038/s41529-021-00165-6 ◽

2021 ◽

Vol 5 (1) ◽

Author(s):

Roman Sherrod ◽

Eric C. O’Quinn ◽

Igor M. Gussev ◽

Cale Overstreet ◽

Joerg Neuefeind ◽

...

Keyword(s):

Long Range ◽

Short Range ◽

Structural Model ◽

Ion Irradiation ◽

Function Analysis ◽

Ion Beam ◽

Structural Response ◽

Heavy Ion ◽

Range Order ◽

Radiation Resistant

AbstractThe structural response of Dy2TiO5 oxide under swift heavy ion irradiation (2.2 GeV Au ions) was studied over a range of structural length scales utilizing neutron total scattering experiments. Refinement of diffraction data confirms that the long-range orthorhombic structure is susceptible to ion beam-induced amorphization with limited crystalline fraction remaining after irradiation to 8 × 1012 ions/cm2. In contrast, the local atomic arrangement, examined through pair distribution function analysis, shows only subtle changes after irradiation and is still described best by the original orthorhombic structural model. A comparison to Dy2Ti2O7 pyrochlore oxide under the same irradiation conditions reveals a different behavior: while the dysprosium titanate pyrochlore is more radiation resistant over the long-range with smaller degree of amorphization as compared to Dy2TiO5, the former involves more local atomic rearrangements, best described by a pyrochlore-to-weberite-type transformation. These results highlight the importance of short-range and medium-range order analysis for a comprehensive description of radiation behavior.

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Swift heavy ion irradiated spinel ferrite: A cheap radiation resistant material

Nuclear Instruments and Methods in Physics Research Section B Beam Interactions with Materials and Atoms ◽

10.1016/j.nimb.2016.03.052 ◽

2016 ◽

Vol 379 ◽

pp. 235-241 ◽

Cited By ~ 7

Author(s):

M. Satalkar ◽

S.N. Kane ◽

P.K. Kulriya ◽

D.K. Avasthi

Keyword(s):

Spinel Ferrite ◽

Heavy Ion ◽

Resistant Material ◽

Swift Heavy Ion ◽

Radiation Resistant

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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.

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RADIATION EFFECTS IN STAINLESS STEEL AND TUNGSTEN FOR USE IN THE ADS SPALLATION NEUTRON SOURCE SYSTEM

Modern Physics Letters B ◽

10.1142/s0217984903004981 ◽

2003 ◽

Vol 17 (04) ◽

pp. 147-151 ◽

Cited By ~ 4

Author(s):

YONGJUN XU ◽

ZHIQIANG WANG ◽

JIAZHENG ZHU ◽

T. MINAMISONO ◽

K. MATSUTA ◽

...

Keyword(s):

Stainless Steel ◽

Neutron Source ◽

Radiation Effects ◽

316L Stainless Steel ◽

Ion Irradiation ◽

Heavy Ion ◽

Good Choice ◽

Spallation Neutron Source ◽

Radiation Resistant ◽

And Tungsten

Radiation effects have been studied in modified 316L stainless steel and commercially available stainless steel and tungsten by the heavy ion irradiation simulation and positron lifetime techniques. The experimental results show that the radiation resistant property of stainless steel is much better than that of tungsten, and the modified 316L stainless steel is the best among them. The stainless steel is a good choice for the beam window material of the ADS spallation neutron source system, and the modified 316L stainless steel is the best choice.

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Heavy Ion Irradiation of Zirconate Pyrochlores

MRS Proceedings ◽

10.1557/proc-713-jj11.35 ◽

2002 ◽

Vol 713 ◽

Cited By ~ 2

Author(s):

J. Lian ◽

L. M. Wang ◽

J. Chen ◽

R. C. Ewing ◽

K. V. G. Kutty

Keyword(s):

Ion Irradiation ◽

Ion Beam ◽

Amorphous State ◽

Pyrochlore Structure ◽

Fluorite Structure ◽

Heavy Ion ◽

Ionic Radii ◽

Radiation Resistant ◽

A Site ◽

Nuclear Waste Forms

ABSTRACTZirconate pyrochlores, A2Zr2O7, are important potential nuclear waste forms for Puimmobilization. The binary Gd2(Ti2-xZrx)O7 has been shown to have increasing resistance to ionirradiation damage with the increasing Zr content, and Gd2Zr2O7 is radiation resistant to a 1 MeV Kr+ ion irradiation at 25 K to a dose of 5 dpa. In this study, a 1.5 MeV Xe+ irradiation was completed for zirconate pyrochlores A2Zr2O7 (A=La, Nd, Sm, Gd). The radiation resistance decreases with an increase of the ionic radius of A-site cation. La2Zr2O7 is the first zirconate pyrochlore to be amorphized by ion beam irradiation, and the critical amorphization temperature, Tc, is ∼310 K. The susceptibility of La2Zr2O7 to ion beam damage is related to its structure, which shows the largest deviation from the ideal fluorite structure. These results are also consistent with calculations of the cation antisite formation energy in the pyrochlore structure. The ion irradiation-induced pyrochlore-to-fluorite transformation occurred in all of the irradiated zirconate pyrochlore phases. Based on the results for Gd2Ti2-xZrxO7 and A2Zr2O7, the defect fluorite structures are stable when the ionic radii ratio rA/rB≤1.54; beyond this limit, the defect fluorite structure becomes increasingly unstable relative to the amorphous state.

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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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