scholarly journals Comparison of short-range order in irradiated dysprosium titanates

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.

Heavy Ion Irradiation of Zirconate Pyrochlores

2002 ◽  
Vol 713 ◽  
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.

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

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.

SHORT-RANGE AND LONG-RANGE ORDER OF TITANIUM IN Ti1+xS2

1977 ◽  
Vol 38 (C7) ◽  
pp. C7-202-C7-206 ◽  
Author(s):  
R. MORET ◽  
M. HUBER ◽  
R. COMÈS
Keyword(s):  
Long Range ◽  
Short Range ◽  
Range Order ◽  
Long Range Order

Ion beam-mixing effects in nearly lattice-matched AlInN/GaN heterostructures by swift heavy ion irradiation

2012 ◽  
Vol 167 (7) ◽  
pp. 506-511 ◽  
Author(s):  
G. Devaraju ◽  
S. V.S. Nageswara Rao ◽  
N. Srinivasa Rao ◽  
V. Saikiran ◽  
T. K. Chan ◽  
...  
Keyword(s):  
Ion Irradiation ◽  
Ion Beam ◽  
Heavy Ion ◽  
Ion Beam Mixing ◽  
Swift Heavy Ion Irradiation ◽  
Heavy Ion Irradiation ◽  
Mixing Effects ◽  
Swift Heavy Ion ◽  
Lattice Matched
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