Ion Beam-Induced Amorphization of the Pyrochlore Structure-Type: A Review

ABSTRACTThis paper reviews the recent developments in the understanding of the radiation-damage processes in A2B2O7 (Fd3m; Z=8) pyrochlore-structure compounds. Pyrochlore structure compounds display a wide range of behaviors in response to ion beam irradiation. Some compositions, such as Gd2Ti2O7, are amorphized at relatively low doses (∼0.2 dpa at room temperature) while other compositions, such as Gd2Zr2O7, do not amorphize (even at doses of 36 dpa at 25 K) and instead disorder to a defect fluorite structure. The response to ion beam irradiation is highly dependent on compositional changes that affect both the structural distortion from the ideal fluorite structure and the associated energetics of the disordering process. Generally, the ionic size of the cations plays a dominant role in determining the radiation response of different pyrochlore compositions. However, the cation ionic radius ratio criteria cannot be applied all-inclusively in predicting the radiation “tolerance” of a pyrochlore. Systematic irradiation studies of the radiation response of rare-earth (A-site) pyrochlores in which B = Ti, Zr, and Sn have shown that the behavior of the pyrochlore also depends on the cation electronic structure, i.e., the type of bonding, which is closely related to the polyhedral distortion and structural deviation from the ideal fluorite structure. These structural changes affect the dynamic defect recovery process directly linked to the material's response to and recovery from irradiation.

Download Full-text

Ion-beam irradiation of Gd2Sn2O7 and Gd2Hf2O7 pyrochlore: Bond-type effect

Journal of Materials Research ◽

10.1557/jmr.2004.0178 ◽

2004 ◽

Vol 19 (5) ◽

pp. 1575-1580 ◽

Cited By ~ 65

Author(s):

Jie Lian ◽

Rodney C. Ewing ◽

L.M. Wang ◽

K.B. Helean

Keyword(s):

Room Temperature ◽

Ion Beam ◽

Pyrochlore Structure ◽

Fluorite Structure ◽

Structure Type ◽

Radiation Response ◽

Beam Irradiation ◽

Ion Beam Irradiation ◽

Bond Type ◽

Wide Range

Ceramics with III-IV pyrochlore compositions, A3+2B4+2O7 (A = Y and rare earth elements; B = Ti, Zr, Sn, or Hf), show a wide range of responses to ion-beam irradiation. To evaluate the role of the B-site cations on the radiation stability ofthe pyrochlore structure-type, Gd2Sn2O7 and Gd2Hf2O7 have been irradiated by1 MeV Kr+. The results are discussed in terms of the ionic size and type ofbonding of Sn4+ and Hf4+ and compared to previous results for titanate andzirconate pyrochlores. Gd2Sn2O7 is sensitive to ion beam–induced amorphizationwith a critical amorphization dose of approximately 3.4 displacements per atom(dpa) (2.62 × 1015 ions/cm2) at room temperature and a critical amorphization temperature of approximately 350 K. Gd2Hf2O7 does not become amorphous at adose of approximately 4.54 displacement per [lattice] atom (3.13 × 1015 ions/cm2) at room temperature, but instead is transformed to a disordered fluorite structure upon ion-beam irradiation. Although the radius ratio of the A- to B-site cations provides a general indication of the type of radiation response of different pyrochlore compositions, the results for Gd2Sn2O7 emphasize the importance of bond type, particularly the covalency of the 〈Sn–O〉 bond in determining the radiation response.

Download Full-text

In-situ observation of structural changes in aluminum during He+ and H2+ dual-ion beam irradiation

Journal of Nuclear Materials ◽

10.1016/0022-3115(92)90668-b ◽

1992 ◽

Vol 191-194 ◽

pp. 1219-1223 ◽

Cited By ~ 1

Author(s):

S. Furuno ◽

K. Hojou ◽

K. Izui ◽

N. Kamigaki ◽

K. Ono ◽

...

Keyword(s):

Structural Changes ◽

Ion Beam ◽

In Situ Observation ◽

Beam Irradiation ◽

Ion Beam Irradiation

Download Full-text

Structural Changes of Makrofol Polymer due to Argon Ion Beam Irradiation

Journal of Nuclear Energy Science & Power Generation Technology ◽

10.4172/2325-9809.1000130 ◽

2015 ◽

Vol 04 (01) ◽

Cited By ~ 1

Author(s):

Helal AG Nouh SA

Keyword(s):

Structural Changes ◽

Ion Beam ◽

Beam Irradiation ◽

Ion Beam Irradiation ◽

Argon Ion

Download Full-text

Improving the Thermal Stability of Photoresist Films by Ion Beam Irradiation

MRS Proceedings ◽

10.1557/proc-504-443 ◽

1997 ◽

Vol 504 ◽

Cited By ~ 1

Author(s):

F. C. Zawislak ◽

Irene T. S. Garcia ◽

D. Samios ◽

D. L. Baptista ◽

P. F. P. Fichtner ◽

...

Keyword(s):

Thermal Stability ◽

Energy Density ◽

Structural Changes ◽

Considerable Increase ◽

Ion Beam ◽

Cross Linking ◽

Beam Irradiation ◽

Ion Beam Irradiation ◽

Large Loss ◽

Thermal Stability Of

ABSTRACTThe thermal stability of ion irradiated 1.7 μm thick AZ-1350J photoresist films was investigated using the RBS and ERDA techniques to measure the composition of the irradiated and annealed films. The films have been irradiated with He, N and Ar ions at energies from 380 to 760 keV and fluences between 2 × 1015 and 1016 ions cm−2. A considerable increase in the thermal stability of the He irradiated film is observed from ≈200°C – when the non-irradiated film starts to decompose – to 400°C after the irradiation. The FTIR spectroscopy and the SEM observations were used to study the chemical structural changes and the surface morphology of the irradiated samples. The results are discussed in terms of the energy density deposited by the ions, the large loss of H during irradiation, and the resulting increase in cross-linking density.

Download Full-text

Structural changes induced in graphene oxide film by low energy ion beam irradiation

Radiation Physics and Chemistry ◽

10.1016/j.radphyschem.2021.109923 ◽

2021 ◽

pp. 109923

Author(s):

Chetna Tyagi ◽

Ambuj Tripathi ◽

Arka Bikash Dey ◽

D.K. Avasthi

Keyword(s):

Graphene Oxide ◽

Oxide Film ◽

Structural Changes ◽

Ion Beam ◽

Low Energy ◽

Beam Irradiation ◽

Ion Beam Irradiation

Download Full-text

Ion-beam irradiation and 244Cm-doping investigations of the radiation response of actinide-bearing crystalline waste forms

Journal of Materials Research ◽

10.1557/jmr.2015.23 ◽

2015 ◽

Vol 30 (9) ◽

pp. 1516-1528 ◽

Cited By ~ 3

Author(s):

Sergey V. Yudintsev ◽

Andrey A. Lizin ◽

Tatiana S. Livshits ◽

Sergey V. Stefanovsky ◽

Sergey V. Tomilin ◽

...

Keyword(s):

Ion Beam ◽

Radiation Response ◽

Beam Irradiation ◽

Ion Beam Irradiation ◽

Waste Forms ◽

Image Position

Abstract

Download Full-text

Studying Radiation Damage in Structural Materials by Using Ion Accelerators

Reviews of Accelerator Science and Technology ◽

10.1142/s1793626811000513 ◽

2011 ◽

Vol 04 (01) ◽

pp. 161-182 ◽

Cited By ~ 16

Author(s):

Peter Hosemann

Keyword(s):

Radiation Damage ◽

Large Scale ◽

Ion Beam ◽

Structural Materials ◽

Limiting Factor ◽

Particle Accelerators ◽

Beam Irradiation ◽

Ion Beam Irradiation ◽

Short Period ◽

Wide Range

Radiation damage in structural materials is of major concern and a limiting factor for a wide range of engineering and scientific applications, including nuclear power production, medical applications, or components for scientific radiation sources. The usefulness of these applications is largely limited by the damage a material can sustain in the extreme environments of radiation, temperature, stress, and fatigue, over long periods of time. Although a wide range of materials has been extensively studied in nuclear reactors and neutron spallation sources since the beginning of the nuclear age, ion beam irradiations using particle accelerators are a more cost-effective alternative to study radiation damage in materials in a rather short period of time, allowing researchers to gain fundamental insights into the damage processes and to estimate the property changes due to irradiation. However, the comparison of results gained from ion beam irradiation, large-scale neutron irradiation, and a variety of experimental setups is not straightforward, and several effects have to be taken into account. It is the intention of this article to introduce the reader to the basic phenomena taking place and to point out the differences between classic reactor irradiations and ion irradiations. It will also provide an assessment of how accelerator-based ion beam irradiation is used today to gain insight into the damage in structural materials for large-scale engineering applications.

Download Full-text