skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Oxygen diffusion and oxide phase formation in iron under swift heavy ion irradiation

Abstract

While irradiating thin iron films deposited on silicon wafers with swift heavy ions in the energy range of a few MeV/amu, we have observed that the iron surface oxidizes due to the residual oxygen in the irradiation chamber, induced by the energy deposition by the ion. We have investigated these processes in detail using Rutherford backscattering spectrometry and conversion electron Moessbauer spectroscopy. We found that two different types of oxidation processes were active, depending on the electronic energy loss of the incident ions. Irradiations above the track formation threshold S{sub ec}{sup Fe} of iron resulted in diffusion-controlled dissolution of oxygen in the iron bulk. Below S{sub ec}{sup Fe}, but above the track formation threshold of iron oxide, chemical reaction and homogeneous oxide phase formation took place in a surface layer, while almost no oxygen diffusion into the iron bulk could be observed anymore. These phenomena are discussed in terms of the oxygen mobility in the excited ion tracks in iron and iron oxide. The effective diffusion constant estimated for swift heavy ion induced oxygen diffusion in iron is larger by a factor of 100-1000 than the one reported for thermally activated oxygen diffusion in molten iron.

Authors:
;  [1]
  1. Institut fuer Strahlenphysik, Universitaet Stuttgart, Allmandring 3, 70569 Stuttgart (Germany)
Publication Date:
OSTI Identifier:
20976671
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. B, Condensed Matter and Materials Physics; Journal Volume: 75; Journal Issue: 5; Other Information: DOI: 10.1103/PhysRevB.75.054107; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; DIFFUSION; ELECTRONS; ENERGY LOSSES; HEAVY IONS; ION BEAMS; ION MOBILITY; IRON; IRON OXIDES; IRRADIATION; LAYERS; MEV RANGE; MOESSBAUER EFFECT; OXIDATION; OXYGEN; PARTICLE TRACKS; RUTHERFORD BACKSCATTERING SPECTROSCOPY; SILICON; SURFACES; THIN FILMS

Citation Formats

Roller, Tobias, and Bolse, Wolfgang. Oxygen diffusion and oxide phase formation in iron under swift heavy ion irradiation. United States: N. p., 2007. Web. doi:10.1103/PHYSREVB.75.054107.
Roller, Tobias, & Bolse, Wolfgang. Oxygen diffusion and oxide phase formation in iron under swift heavy ion irradiation. United States. doi:10.1103/PHYSREVB.75.054107.
Roller, Tobias, and Bolse, Wolfgang. Thu . "Oxygen diffusion and oxide phase formation in iron under swift heavy ion irradiation". United States. doi:10.1103/PHYSREVB.75.054107.
@article{osti_20976671,
title = {Oxygen diffusion and oxide phase formation in iron under swift heavy ion irradiation},
author = {Roller, Tobias and Bolse, Wolfgang},
abstractNote = {While irradiating thin iron films deposited on silicon wafers with swift heavy ions in the energy range of a few MeV/amu, we have observed that the iron surface oxidizes due to the residual oxygen in the irradiation chamber, induced by the energy deposition by the ion. We have investigated these processes in detail using Rutherford backscattering spectrometry and conversion electron Moessbauer spectroscopy. We found that two different types of oxidation processes were active, depending on the electronic energy loss of the incident ions. Irradiations above the track formation threshold S{sub ec}{sup Fe} of iron resulted in diffusion-controlled dissolution of oxygen in the iron bulk. Below S{sub ec}{sup Fe}, but above the track formation threshold of iron oxide, chemical reaction and homogeneous oxide phase formation took place in a surface layer, while almost no oxygen diffusion into the iron bulk could be observed anymore. These phenomena are discussed in terms of the oxygen mobility in the excited ion tracks in iron and iron oxide. The effective diffusion constant estimated for swift heavy ion induced oxygen diffusion in iron is larger by a factor of 100-1000 than the one reported for thermally activated oxygen diffusion in molten iron.},
doi = {10.1103/PHYSREVB.75.054107},
journal = {Physical Review. B, Condensed Matter and Materials Physics},
number = 5,
volume = 75,
place = {United States},
year = {Thu Feb 01 00:00:00 EST 2007},
month = {Thu Feb 01 00:00:00 EST 2007}
}
  • Low temperature photoluminescence and optical absorption studies on 200 MeV Ag{sup +15} ion irradiated Co-implanted ZnO thin films were studied. The Co clusters present in as implanted samples were observed to be dissolved using 200 MeV Ag{sup +15} ion irradiation with a fluence of 1x10{sup 12} ions/cm{sup 2}. The photoluminescence spectrum of pure ZnO thin film was characterized by the I{sub 4} peak due to the neutral donor bound excitons and the broad green emission. The Co-doped ZnO films show three sharp levels and two shoulders corresponding to 3t{sub 2g} and 2e{sub g} levels of crystal field splitted Co dmore » orbitals, respectively. The ultraviolet-visible absorption spectroscopy also shows the systematic variation of band gap after 200 MeV Ag{sup +15} ion irradiation.« less
  • The influence of the oxide thickness in the surface tracks formation in thin silicon dioxide layered-silicon substrate (SiO{sub 2}-Si) irradiated with swift heavy ion is dealt with. In this respect, SiO{sub 2}-Si samples with different oxide thicknesses have been characterized using atomic force microscopy before and after 7.51 MeV/u Xe ion irradiation at a grazing incident angle of 1 deg. relative to the surface plane. Experimental evidence of the existence of a threshold thickness in the formation of swift heavy ion-induced surface tracks has been addressed and discussed according to the thermal spike theory. This experimental upshot can be helpfulmore » when assessing metal-oxide-semiconductor ultrathin-gate oxide reliability issues and for growth of silicon-based nanostructures.« less
  • Irradiation of single-crystalline InP with swift heavy ions (SHI's) causes the formation of ion tracks for certain irradiation temperatures if the electronic energy deposition exceeds a threshold value. With increasing SHI fluence, more and more ion tracks are formed, until a continuous amorphous layer is produced due to the multiple overlapping of the tracks at high ion fluences. Single-crystalline InP samples were irradiated either at liquid nitrogen temperature (LNT) or at room temperature (RT) with Kr, Xe, or Au ions with specific energies ranging from ca. 0.3 to 3.0 MeV/u. Afterwards, the samples were investigated by means of Rutherford backscatteringmore » spectrometry and transmission electron microscopy in the plan-view and cross-section geometry. We show that the experimental data obtained can be qualitatively and quantitatively described on the basis of the inelastic thermal spike (TS) model, which was originally used only for metallic targets. The presented extension of the TS model on semiconductors covers mainly the very first stage of the energy transfer from SHI's (so-called 'ionization spikes'). Our results show that the extended TS model offers a self-consistent way to explain the influence of various irradiation conditions (ion mass, ion energy, irradiation temperature, etc.) on the ion track formation and damage accumulation in InP and, therefore, can make a contribution to a better understanding of the underlying mechanisms. Further, our results prejudice the amenity of a single value of the threshold electronic energy loss as a fundamental quantity that is commonly used for the description of track formation in solids irradiated with different ion species. There is no universal RT threshold for track formation in InP, but it is noticeably higher for lighter ions (12.0 and 14.8 keV/nm for RT irradiations with Au and Xe, respectively). Our experimental and simulation results support the idea that the formation of visible tracks requires a predamaging of the material, unless each SHI penetrating perfectly ordered virgin InP directly produces a track that is large enough to be stable.« less
  • In the present study, we probe into the phase transition from anatase to rutile in nanocrystalline thin films under thermal annealing and swift heavy ion (SHI) irradiation. TiO{sub 2} thin films were prepared through chemical route using sol-gel and spin coating techniques on silicon (100) substrates. The structural studies of the annealed films were characterized by GAXRD and Raman spectroscopy. Though thermal annealing is known to cause transformation from anatase to rutile phase of TiO{sub 2} in a temperature interval of 700 to 900 C, in nanoparticle thin films, we found {approx}35 vol% of anatase still remains even after annealingmore » at 1000 C. SHI irradiation by 200 MeV Ag ions on the other hand resulted in complete conversion to rutile phase at fluence of 3x10{sup 12} ions.cm{sup -2}. SHI induced thermal spike seems to be responsible for conversion of anatase to rutile phase.« less