Single-crystal specimen of high-temperature superconductor Bi2Sr2CaCu2Ox was irradiated with 3.5 GeV Xe ions at room temperature up to 1.0 × 1011 ion/cm2. Significant enhancement of magnetization by the irradiation was confirmed. The irradiated specimens were studied by using a high-resolution transmission electron microscope with field emission electron gun (FE-TEM), and, also, with an energy dispersive x-ray analyzer (EDS). Columnar defects with diameter of about 6 nm were observed along the incident ion tracks. By nanoscale high-resolution x-ray spectrochemical analysis across the columnar defect, enrichment of Cu and depletion of Bi, Sr and Ca in the columnar defect center, and vice versa in the outskirts of the defect, was found for the first time. Oxygen depletion in the defect, and increased distribution outside of the defect were also found by electron energy loss spectroscopy. This experimental evidence suggests that the columnar defects are formed as a consequence of Coulomb explosion induced by the electronic excitation of the high-energy heavy ions.

Radiation is known to cause point defects formation in different materials. In the case of cubic SiC single crystal radiation flux on the order of 2·1020 neutrons/cm2 at 0.18 MeV causes over 3% volume lattice expansion. Radiation-induced strain (measurable by X-Ray diffraction) can be relieved when the annealing temperature exceeds the temperature of irradiation. Based on this effect the original technology of maximum temperature measurement was developed a while ago. Single crystal SiC sensor small size (200–500 microns), wide temperature range (150–1450 °C), “no-lead” installation, and exceptional accuracy make it very attractive for use in small, rotating and “hard-to-access” parts, including, but not limited to gas turbine blades, space shuttle ceramic tiles, automobile engines, etc. With the advances in X-Ray diffraction measurements, crystal and thin film growth techniques, it is the time to revise and update this technology. Modeling radiation damage, as well as annealing effects are also beneficial.

Silica is one of the candidate materials for final focusing mirrors in inertial fusion reactors. This material will be exposed to high neutron irradiation fluxes during operation. Radiation damage results in point defects that can lead to obscuration of this material; that is, degradation of the optical properties of silica. In this paper we present molecular dynamic simulations of defect production in silica glass. Results on the threshold displacement energies due to oxygen Primary Knock-on Atoms (PKA) are reported concluding that a range of energies (20–40 eV) exists in which the defects have a probability to be created. In addition, we determine a range of distances for a PKA to become a stable defect out of its original position. Our present analysis is focused on the formation of Oxygen Deficient Centers (ODC).

The beneficial roles energetic ions play in thin film vacuum processes have long been recognized by the vacuum coating community. Optical coaters were among the first to adopt the process in the form of concurrent, low energy, directed ion beam bombardment of physical vapor deposition [electron beam] coatings for producing dense, adherent, robust, and environmentally resistant optical coatings. The international research and development community has also been actively pursuing the study of ion beam assisted deposition (IBAD) for both studying the mechanisms of ion/solid interactions during thin film growth as well as for developing coating protocols for specific application areas, including: tribological coatings, anti-corrosion coatings, optical coatings, superconducting buffer layers and coatings for temperature sensitive substrates such as polymers. This paper will review selected areas of this active field and will attempt to identify emerging application areas.

Electrical properties of rutile (TiO2) single crystals irradiated by high-fluence-reactor neutrons have been investigated for the first time. In this paper, the colorless rutile single crystal turns into dark blue after being irradiated by high-fluence-reactor neutrons of 1019/cm2 and its electrical properties change, from high insulator to normal semiconductor. The relationship of sample resistance to temperature (at low temperature, room temperature and high temperature, respectively) and the effect of annealing atmosphere (in air or in vacuum) on the electrical property of the sample have been studied. The results show that the sample has semiconductor properties at low temperature. At high temperature, however, it is oxidized into colorless insulator in air and the activation energy gradual changes due to slow oxidization process. In 10-4 Pa vacuum condition, TiO2 becomes a semiconductor due to the presence of ion defects. The electrical conductance mechanism is also discussed.

A ferritic steel T91 and an oxide dispersion strengthened (ODS) martensitic steel 9Cr-ODS were irradiated with 5 MeV Ni ions at 500°C at a dose rate of 1.38×10-3 dpa/s to doses of 5, 50 and 150 dpa. Both alloys are iron-based with 9Cr and have been designed for use in higher temperature energy systems. However, the radiation effects on these two alloys are not well characterized. For T91, the irradiated microstructure was dominated by tangled dislocation and precipitates, similar to the unirradiated condition except the presence of large dislocation loops of type a<100>. The microstructure of alloy 9Cr-ODS for both the unirradiated and irradiated cases was dominated by dense dislocations, precipitates and yttrium oxides particles and no dislocation loops were observed. The average size of yttrium oxides particles slightly decreased with dose from 11.8 nm for the unirradiated to 9.1 nm at 150 dpa. No voids were detected for both alloys up to a dose of 150 dpa.

Ordered nanoporous alumina has recently been considered as a template for pattern transfer by MeV ion irradiation. Porous alumina of thickness 500 nm has already been used as a mask for low energy heavy ion implantation. However, in order to apply this material as a template for production of structures with higher aspect ratios, lighter ions with MeV energies and larger penetration depth should be used. The aim of this contribution is to examine the transmission of such ions through alumina templates with sufficient thickness to mask ions that are not passing the pores. A careful orientation of the pores in the direction of the incident beam is therefore needed since the acceptance angle for ions passing through the pores decreases with increasing thickness.

Typical size of pores in the investigated alumina foils was 70 nm with a repetition frequency of 100 nm. Transmission through the foil and the energy of transmitted MeV ions were measured for aligned alumina foils by standard backscattering technique. It was shown that the sample transmission is a characteristic of each sample, but for some investigated samples the proportion of transmitted ions was the same as the relative area covered by pores. The energy spectra of transmitted ions were used to further evaluate the quality of foil templates for pattern transfer. It was shown that 2 μm thick alumina films can mask 3 MeV O+ ions, which can be used for ion lithography in polymer materials.

In order to understand the characteristics of surface modification process with cluster ion irradiation, molecular dynamics simulations of Ar cluster impacting on Si surface with various surface structures were carried out. It was found that the surface morphology is dynamically deformed with only one cluster impact and the impact process of cluster is different depending on the local surface structure. For example, when an Ar2000 cluster accelerated with 20keV impacted on the convex point of the surface, the hill was compressed and the impact area was smoothed. At the impact on a concave point, a deeper crater was formed compared with the impact on a flat surface. On the other hand, the MD simulations of sequential impacts of large clusters were performed. It was found that the small tip structures on the surface could be removed easily with cluster irradiation. It was shown that surface roughness converges to 15∼20Å and this value agrees with the result obtained by single impact of cluster.

The evaluation of the damage generated in crystalline ceramic oxides placed in a radiative environment is a major challenge in many technological domains. The use of the channeling technique is particularly well adapted to measure the depth distribution of the irradiation-induced disorder and to monitor the damage build-up. This paper describes the methodology used for the study of radiation damage with the channeling technique, presents a new method of analysis of channeling data based on Monte-Carlo simulations and provides recent results concerning the damage induced in ion-bombarded ceramic oxide single crystals in both nuclear (low-energy ion irradiation) and electronic (high-energy ion irradiation) slowing-down regimes.

Au-ions were implanted at RT conventionally and through a mask into TiO2- and SrTiO3-single crystals with doses in the range from 1×1015Au+/cm2 to 1×1017Au+/cm2, and dose rates of ∼1011ions/sec and ∼3×1013ions/sec, at an energy of 260keV; some samples subsequently were annealed at temperatures up to 1100K. The Au-atoms precipitated to nanocrystals during implantation with an average particle size of 1.5nm. HRTEM investigations revealed that the Au-nanocrystals, embedded in amorphous TiO2-regions, have a broad size distribution varying from large sizes in the near surface region to smaller sizes at larger depths. In the annealing process a coarsening and a reorientation of the Au-nanocrystals is observed. At 1000K the particle size of the textured Au-implant was evaluated to be ∼6nm. Implantation with a high dose rate performed through a metal mask with holes of 120μm diameter and without annealing resulted in an almost equidistant arrangement of the Au-nanocrystals with a narrow size distribution of 2–6nm in TiO2 and 3–5nm in SrTiO3 in the near surface region. Au-ion implantation through an e-beam resist mask (50nm × 50nm holes), with doses ranging from 1×1015Au+/cm2 to 4×1015Au+/cm2 at the low dose rate and annealed at 1000K, lead to a periodic structure of the Au-nanocrystals. The nanocrystal size, evaluated from TEM analysis, in the as-implanted state was ∼5nm and after annealing at 1000K sizes of several nanometers to several tens of nanometers were observed.

Bromine Ion Beam Assisted Etching (Br-IBAE) is shown to be useful in removing GaSb wafer chemical mechanical polish (CMP) surface and subsurface damage; creating microstructure patterns in GaSb surfaces through stencil, photoresist, and oxides masks; and stabilizing the as-etched GaSb surface with a thin, easily thermally desorbed oxide layer. Thus, the Br-IBAE technique is well suited as a GaSb surface final-polish technique in overgrowth applications that require “epi-ready” GaSb (100) surfaces for molecular beam epitaxy (MBE) as well as applications such as quantum wires and dots that require high-quality GaSb/AlInGaSb MBE overgrowth over patterned GaSb (100) surfaces.

We have investigated proton beam irradiation effects on TlH2PO4 (TDP) showing an antiferroelectric phase transition and a ferroelastic phase transition. The sample was irradiated by 1 MeV proton beams to a dose of 1015 ions/cm2 and studied by means of 1H NMR measurements. The NMR rotating-frame spin-lattice relaxation time was measured as a function of temperature, and analyzed in order to understand the proton motions and the order parameter reflecting the structural changes caused by the proton irradiation.

Spatio-temporal nanostructural fluctuations brought about by transient, metastable atom-cluster formation and the manifold nature of inherent atomic ordering in electron-irradiation-amorphized NiTi were investigated by using a combination of in situ observations inside a high-resolution high-voltage electron microscope (HR-HVEM) and image analyses of molecular-dynamics-simulated atom configurations. Nanometer-sized clusters were found to appear and disappear in the irradiated region. The random formation and annihilation of such nanoclusters are believed to be responsible for nanostructural fluctuations which appear to be related to transitions among manifold inherent structural states, involving multirelaxation processes. Temporal fluctuations in the amorphized structure were manifested through the dose-dependent local amorphization parameter, potential energy, volume, and inherent cluster bonding. The observed fluctuations obey a universal power law. Within the framework of the multi-Lorentzian picture, the resultant power law describes the distribution of multirelaxation times or cluster lifetimes. In addition, a unified relation for the temporal autocorrelation function for such fluctuation phenomena has been determined.

Electron and ion irradiation-induced nanostructures in an iron phosphate glass with a composition of 45 mol%Fe2O3-55 mol%P2O5 have been characterized by advanced electron microbeam techniques. Analysis by energy-filtered transmission electron microscopy indicated that Fe-rich and P-rich nanophases were formed when the glass was irradiated under a broad (with a diameter of 1.2μm) electron beam [give the dose range]. Phase separation developed with the increase in electron dose (from 1.0×1026e/m2 to 4.8×1026e/m2) as a result of the formation of an Fe-rich phase and pure P-phase. The formation of the Fe-rich and the P-phases are thought to be due to mainly ionization process. Under a low energy ion beam irradiation, Fe/FeO nanoparticles were formed, as confirmed by selected-area electron diffraction analysis. However, no nanoparticles were observed under a high-energy high-dose ion irradiation. The ion beam-irradiation results suggest that the formation of the Fe/FeO nanoparticles was due to preferential sputtering during ion irradiation and that the nanoparticles lie within the surface layers of the glass.

Ar penetration during gas cluster ion beam (GCIB) irradiation has been investigated using secondary ion mass spectroscopy (SIMS). The concentration of Ar rose to a maximum and then decreased gradually with increasing depth. The depth of the Ar penetration peak increased in proportion to the cube root of the acceleration voltage of GCIB and was independent of ion dose. Ar penetration was attributed to fast neutrals in the GCIB and was successfully suppressed by decreasing the pressure of the space downstream of the GCIB or decreasing the monomer ion density in order to suppress charge transfer collisions.

Extended defects formed by antimony ion implantation in Si(100) was investigated as a function of the implant energy. The implanted layer was examined by cross-sectional electron microscopy (TEM). Post-implantation spike-annealing was also performed from 950°C to 1095°C to examine evolution of defects. From the TEM study, the threshold energy to induce visible defects for Sb implantation was found to be more than 50 keV. A mapping for the location of defects was constructed by TEM and secondary ion mass spectroscopy (SIMS). The end-of-range (EOR) defects, which were possibly formed during the solid phase epitaixy regrowth, were located near the lower bound of the transition region. For 70-keV implantation, extended defects appear at the near-surface and the EOR region. It was observed that the near-surface defects diminished after annealing at more than 1050°C, while the EOR defects became coarsening at 1095°C.