Radiation Effects in Amorphous Metallic Alloys as Revealed by Mössbauer Spectrometry: Part II. Ion Irradiation

Due to their excellent magnetic properties, amorphous metallic alloys (AMAs) are considered for the construction of magnetic cores of radio-frequency cavities in accelerators. Here, they might be exposed to ion bombardment. The influence of irradiation by both light and heavy ions featuring low and high energies, respectively, is followed by the techniques of 57Fe Mössbauer spectrometry. Modifications of surface layers in selected Fe-containing AMAs after ion irradiation are unveiled by detection of conversion electrons and photons of characteristic radiation whereas those in their bulk are derived from standard transmission spectra. Rearrangement of microstructure which favors the formation of magnetically active regions, is observed in surface regions bombarded by light ions. Heavy ions caused pronounced effects in the orientation of net magnetization of the irradiated samples. No measurable impact upon short-range order arrangement was observed. Part I of this paper is devoted to radiation effects in Fe-based AMAs induced by neutron irradiation.

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Radiation Effects in Amorphous Metallic Alloys as Revealed by Mössbauer Spectrometry: Part I. Neutron Irradiation

Metals ◽

10.3390/met11050845 ◽

2021 ◽

Vol 11 (5) ◽

pp. 845

Author(s):

Marcel B. Miglierini

Keyword(s):

Neutron Irradiation ◽

Radiation Effects ◽

Ion Irradiation ◽

Hyperfine Magnetic Field ◽

Mössbauer Spectrometry ◽

Metallic Alloys ◽

Hyperfine Fields ◽

Spectral Parameters ◽

Amorphous Metallic Alloys ◽

Mossbauer Spectrometry

Iron-based amorphous metallic alloys (AMAs) of several compositions were exposed to neutron irradiation with fluences of up to 1019 n/cm2. These materials exhibit excellent magnetic properties which predetermine them for use in electronic devices operated also in radiation-exposed environments. Response of the studied AMAs to neutron irradiation is followed by Mössbauer spectrometry which probes the local microstructure. Neutron irradiation leads to rearrangement of constituent atoms, their clustering, and formation of stress centers. The observed modifications of topological short-range order result in changes of spectral parameters including average hyperfine magnetic field, , standard deviation of the distribution of hyperfine fields, and position of the net magnetic moment. After irradiation, especially differences in -values develop in two opposite directions. This apparent controversy can be explained by formation of specific atomic pairs with different exchange interactions, which depend on the composition of the samples. Part II of this paper will be devoted to radiation effects caused in Fe-based AMAs by ion irradiation.

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Comparison of the radii of latent tracks induced by high-energy heavy ions in Y3Fe5O12by HREM, channelling Rutherford backscattering and Mössbauer spectrometry

Philosophical Magazine A ◽

10.1080/01418618808209954 ◽

1988 ◽

Vol 58 (5) ◽

pp. 799-808 ◽

Cited By ~ 64

Author(s):

M. Toulemonde ◽

F. Studer

Keyword(s):

Heavy Ions ◽

Mössbauer Spectrometry ◽

High Energy ◽

Rutherford Backscattering ◽

Mossbauer Spectrometry

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Dose Rate Effects During Damage Accumulation in Silicon

MRS Proceedings ◽

10.1557/proc-438-89 ◽

1996 ◽

Vol 438 ◽

Author(s):

M.-J. Caturla ◽

T. Diaz de la Rubia

Keyword(s):

Molecular Dynamics ◽

Monte Carlo ◽

Dose Rate ◽

Heavy Ions ◽

Damage Accumulation ◽

Ion Irradiation ◽

Monte Carlo Model ◽

Dose Rate Effects ◽

Rate Effects ◽

Light Ions

AbstractWe combine molecular dynamics and Monte Carlo simulations to study damage accumulation and dose rate effects during irradiation of Silicon. We obtain the initial stage of the damage produced by heavy and light ions using classical molecular dynamics simulations. While heavy ions like As or Pt induce amorphization by single ion impact, light ions like B only produce point defects or small clusters of defects. The amorphous pockets generated by heavy ions are stable below room temperature and recrystallize at temperatures below the threshold for recrystallization of a planar amorphous-crystalline interface. The damage accumulation during light ion irradiation is simulated using a Monte Carlo model for defect diffusion. In this approach, we study the damage in the lattice as a function of dose and dose rate. A strong reduction in the total number of defects left in the lattice is observed for lower dose rates.

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Damage Accumulation and Annealing in Ion Irradiated Silicon

MRS Proceedings ◽

10.1557/proc-201-345 ◽

1990 ◽

Vol 201 ◽

Cited By ~ 1

Author(s):

F. Priolo ◽

A. Battaglia ◽

C. Spinella ◽

E. Rimini

Keyword(s):

Substrate Temperature ◽

Single Crystal ◽

Heavy Ions ◽

Damage Accumulation ◽

Ion Irradiation ◽

High Energy ◽

Doping Content ◽

Damage Morphology ◽

Light Ions

AbstractThe evolution of pre-existing damage structures in Si under high energy ion irradiation is discussed. Different initial morphologies are investigated: a sample partially pre-damaged with heavy ions and a sample partially pre-damaged with light ions are compared within them and with an undamaged single crystal. It is shown that ion irradiation can produce either damage accumulation, in the form of amorphous regions, or damage annealing depending on the pre-existing damage morphology, on the substrate temperature, and on the doping content in the irradiated layer. These data are discussed and interpreted on the basis of the existing models on ion induced amorphization and crystallization.

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