Ion Beam Analysis Research Articles

A New High-Throughput Focused MeV Ion-Beam Analysis Setup

The analysis of material composition by ion-beam analysis (IBA) is becoming a standard method, similar to electron microscopy. A pool of IBA methods exists, from which the combination of particle-induced-X-ray emission (PIXE), particle induced gamma-ray analysis (PIGE), nuclear-reaction-analysis (NRA), and Rutherford-backscattering-spectrometry (RBS) provides the most complete analysis over the whole periodic table in a single measurement. Yet, for a highly resolved and accurate IBA analysis, a sophisticated technical setup is required integrating the detectors, beam optics, and sample arrangement. A new end-station developed and installed in Forschungszentrum Jülich provides these capabilities in combination with high sample throughput and result accuracy. Mechanical tolerances limit the device accuracy to 3% for RBS. Continuous pumping enables 5 × 10−8 mbar base pressure with vibration amplitudes < 0.1 µm. The beam optics achieves a demagnification of 24–34, suitable for µ-beam analysis. An in-vacuum manipulator enables scanning 50 × 50 mm² sample areas with 10 nm accuracy. The setup features the above-mentioned IBA detectors, enabling a broad range of analysis applications such as the operando analysis of batteries or the post-mortem analysis of plasma-exposed samples with up to 3000 discrete points per day. Custom apertures and energy resolutions down to 11 keV enable separation of Fe and Cr in RBS. This work presents the technical solutions together with the quantification of these challenges and their success in the form of a technical reference.

Energy deposition by nonequilibrium charge states of MeV I127 in Au

The energy loss of iodine ions at initial charge states up to 25+ and energies up to 36 MeV in self-supporting gold foils between 37 and 107 nm of thickness was measured with an electron mirror type time-of-flight detector. An excess energy loss of 130 keV was observed at 36 MeV for charge state 25+ compared to 16+, and an energy loss deficit of 100 keV was observed for charge state 8+. The charge state equilibration length for 36-MeV iodine was estimated to lie between 3 and 7 nm, corresponding to an equilibration time between 0.4 and 0.9 fs. This result is relevant both for nanostructure fabrication with MeV ion beams and for depth profiling based on ion beam analysis data in cases where the charge state of the primary ion is far from the equilibrium value in the sample under study. A comparison to published data on charge state equilibration for various projectile-target combinations and energies from 10 keV to 6 GeV indicated that the energy scaling of the equilibration length observed at high energy is invalid for projectile velocities on the order of the Bohr velocity and below. The measurement further provided equilibrium values of the electronic stopping power for iodine in gold at ten energies between 10 and 36 MeV.

Symmetries of 13C tracer deposition in EAST D and He plasmas investigated on the sub-mm to 100 mm scale by deuteron nuclear reaction analysis

In continuation of an earlier study, this work focusses on deposit analysis in the mm region around the tracer injection hole of two 13CD4 injection experiments in EAST by using focussed 1.43 MeV deuteron ion beam analysis. This study adds ∼1500 data points to the former work on the same samples to assess more details on deposition patterns and symmetry and test the accuracy of former extrapolations.Mapping of the 13CD4 injection-hole vicinity using 0.2 mm lateral resolution yields compatible results as the former 1.8 mm resolution for the local co-deposit thickness. The new data reveal the deposition maximum to be 1 ± 0.2 mm away from the injection hole towards the ExB direction, resembling the triangular shape also seen on the larger scale. The analysis of 3 blocks along the magnetic field vector shows a dominant deposition along the surface area closest to the last closed flux surface. An edge with a factor ∼11 drop in deposit thickness within 2 mm spans here along the whole 150 mm tile size and along the axis of the magnetic field. The analysis using proton backscattering shows no He retention in the He plasma exposed co-deposits above the 1 % limit of detection.The total deposited 13C amount was underestimated by ∼5 % in the former study, a value not exceeding the measurement uncertainty. The combination of ∼0.2 mm spatial resolution around the injection-hole and at the deposit edge with ∼ 2 mm resolution but larger coverage outside these regions is found to provide a reasonable compromise of information quality and analysis effort.

Fingerprinting Australian soils based on their source location

Sampling of PM2.5 has been undertaken twice per week at the Liverpool and Mascot sites (in Sydney, Australia) since 1998. Ion Beam Analysis (IBA) was applied to each sample to determine the concentrations of 21 elements from hydrogen to lead and the black carbon concentration was determined using photon transmission techniques.Sampling days that displayed high and low airborne soil concentrations were identified and three distinct sets of soil fingerprints were determined using Positive Matrix Factorisation (PMF) source apportionment techniques. A fingerprint for all sampling days (representing the average soil fingerprint for each site), a fingerprint corresponding to low soil days associated with local retrained road dust and a fingerprint for high soil days associated with agricultural activities. The ratios of key soil elements (i.e. Si, Al, Fe) displayed larger temporal variation for the high soil days, whereas lower variation was observed for low (local) soil days. Furthermore, it was found that the El Niño-Southern Oscillation (ENSO) affected the concentration of windblown soil dust in the atmosphere.The average soil fingerprint, for all data, was heavily influenced by sampling days containing higher concentrations of soil dust, thus representing the dominant soil type. However, we did observe differences in the K/Fe and Ca/Si ratios to be a distinguishing factor between the average soil fingerprint and the high soil day fingerprint.The Soil fingerprint for the low soil concentration days had a large fraction of black carbon associated with vehicle emissions, represented retrained road dust.

Differential inflammatory and toxic effects in-vitro of wood smoke and traffic-related particulate matter from Sydney, Australia

BackgroundIt is well known that PM2.5 generated by traffic or burning wood is pro-inflammatory and induces various adverse health outcomes in humans. In Sydney, New South Wales, Australia, the main anthropogenic contributors to particulate matter (PM) air pollution are wood combustion heaters, on-road vehicles, and coal-fired power stations. However, the relative toxicity of these local sources has not to date been investigated. MethodPM2.5 was collected on filters from the same sampling site in Liverpool, one suburb of Sydney. According to the positive matrix factorisation and collection season, filters were representative of either day with high traffic-related air pollution (TRAP), wood smoke, or both TRAP and woodsmoke (mixed air pollution). The elemental composition of the PM was assessed by accelerator-based ion beam analysis techniques (i.e. PIXE & PIGE) and size by Dynamic Light Scattering. Toxicity and inflammation were assessed in-vitro in human bronchial epithelial cells by measuring interleukin-6 (IL-6), interleukin-8 (IL-8) release, and MTT. ResultsMixed air pollution (TRAP/wood smoke) PM had more nanometer (nm) sized PM than the other two groups. Using an in-vitro model of the lungs, the mixed air pollution PM was the most toxic, whereas the PM from woodsmoke induced greater IL-6 release than TRAP PM. There was no difference in the induction of IL-8 between the three sources of PM. ConclusionMarked differences occur in the cellular response to PM from different sources, with differences in both toxicity and inflammation.

Thirteenth-century stained glass windows of the Sainte-Chapelle in Paris: An insight into medieval glazing work practices

The restoration of the four northern windows of the 13th century Sainte-Chapelle in Paris from 2011 to 2014 has offered a unique opportunity to investigate the chemical composition and color of medieval glasses. This impressive corpus, covering a total surface of 660 m2, was created in a record time of a few years. The glasses from ten selected panels were analyzed using non-destructive and non-invasive techniques, with a specific consideration for the color of the glasses. Ion beam analyses performed at the New AGLAE facility enabled revealing that all ancient glasses are “potash” type glasses made from plant ashes, likely beech, in agreement with previous results on off-site panels. The multivariate analysis of major and minor elements demonstrates the presence of compositional clusters with a small variability suggesting the identification of bundles of glasses. The coloration of the glasses was measured by optical absorption spectroscopy, using a mobile spectrophotometer over the entire UV–visible-NIR energy range. The color palette is made of six colors assigned to typical medieval recipes. The chromophores of the different glasses are identified by combining the chemical composition, optical absorption spectroscopy and colorimetry. Colorless, yellow and purple glasses arise from the subtle redox equilibrium between manganese and iron. Their reduced usage shows their uncertain production. Blue glasses are colored by Co2+ using saffre from the contemporary German mines, green glasses are colored by Cu2+ and Fe3+ using high concentrations of copper and red glasses are striated glass colored by metallic copper nano-particles. Glass matrix and chromophores form compositional clusters, which are spread among the panels of the four windows suggesting that the glazing of these four windows was run simultaneously by the same atelier using the same supply of glass.

Lithium source for focused ion beam implantation and analysis

We present a new Li source for focused ion beam applications. Based on an AuSi eutectic alloy, Li is added as an impurity to minimize effects from degradation when exposed to air. We show the source is stable over the course of an hour and spot sizes ≲10 nm can be achieved. The Li beam can achieve hundreds of nanometer ranges in semiconductors with minimal damage being generated along the path length. The source performance is evaluated through a high-resolution ion beam induced charge collection experiment on an Si-based detector. Further application of the source for ion beam analysis is numerically explored; the example investigated is based on probing a semiconductor heterostructure through a Rutherford backscattering experiment, where the Li beam can reveal information that is inaccessible with either low energy or high energy He projectiles used as probes.

AIFIRA: a light ion beam facility for ion beam analysis and irradiation

AIFIRA is a small-scale ion beam facility equipped with a single-stage electrostatic accelerator delivering bright beams of light ions (protons, deuterons and helium ions) in the MeV energy range. The facility provides ion beam irradiation, analysis, and imaging techniques to academic research groups and companies. These techniques cover a wide range of applications including materials research, life sciences, environment, geology and geochemistry, archeometry, and applied physics. About 200 days of beam time are allocated each year to internal and external users either coming from local, national, or international teams. AIFIRA is certified as a research platform by its two parent institutions: CNRS/IN2P3 and the university of Bordeaux. Therefore, beamtime allocation is opened to external teams that are accompanied by local experts to prepare, perform and analyze their experiments. This paper describes the facility and the developments performed in the last years. We highlight two original features of the facility: charge collection studies using a microbeam and the production of secondary neutron fields.

Detection of Corrosion in Thick Film Resistors by X-Ray Imaging

In this article, a non-destructive method is presented, using 2D X-ray imaging, to investigate corrosion defects in thick film resistors stressed by two different corrosion experiments, a single gas experiment and a flowers of sulphur experiment. In total, 370 devices under test (DUTs) were investigated, using the 2D X-ray imaging technique, of which 10 were imaged in a sequence of 2D X-ray images to evaluate the corrosion propagation. The observed underlying corrosion product was verified by using focused ion beam analysis combined with an energy dispersive X-ray spectroscopy. The presented 2D X-ray imaging technique enables a fast and non-destructive method for accurately identifying corrosion and corrosion progression in thick film resistors. The presented imaging method was found to be particularly suitable for supplier benchmarking purposes, as well as for the failure analysis of field returns as it allows for a proper corrosion evaluation of surface mount thick film resistors, while keeping the analysed assembly intact.

Damage characteristics of dual-band high reflectors affected by nodule defects in the femtosecond regime

The influence of nodule defects on the characteristics of femtosecond laser-induced damage has not been fully investigated. In this study, two types of 800 nm/1064 nm dual-band HfO2/SiO2 high-reflection films with different configurations were analyzed. Combined with finite-difference time-domain electric field simulation and focused ion beam analysis, the initial state and growth process of femtosecond laser damage of nodules were explored. In particular, the sequence of blister damage determined by the film design and the inner damage caused by nodules were clarified. The rule of the laser-induced damage threshold of different size nodules was obtained. The difference in the damage behavior of nodules in the two types of films was elucidated.

Epitaxial growth of cubic WCy(001) on MgO(001)

Tungsten carbide films are sputter-deposited onto MgO(001) substrates at 400 °C in 5 mTorr Ar - CH4 gas mixtures with CH4 fractions fCH4 = 0.4–6%, yielding total C-to-W ratios x = 0.57–1.25 as determined by ion beam analyses and energy-dispersive X-ray spectroscopy. The C-to-W ratio y in the cubic WCy phase is smaller than x, ranging from y = 0.47–0.68, as determined from lattice constant ao measurements in combination with first-principle calculations that predict an increasing ao = (0.4053 + 0.0295 y) nm for y = 0.3–1.0. This suggests that the cubic phase is stabilized by carbon vacancies and that the layers contain amorphous C with a volume fraction increasing from 4% to 26% for fCH4 = 0.4–6%. X-ray diffraction (XRD) θ-2θ scans, ω-rocking curves, and reciprocal space maps in combination with high-resolution transmission electron microscopy (TEM) indicate the growth of epitaxial rock-salt structure WCy(001) layers with a cube-on-cube epitaxial relationship with the substrate: (001)WC || (001)MgO and [100]WC || [100]MgO. The measured XRD out-of-plane coherence length of 8 – 14 nm is nearly independent of the film thickness d = 10 or 600 nm, suggesting that growth beyond d = 10 nm leads to an epitaxial breakdown and the nucleation of misoriented hexagonal or orthorhombic W2C grains for fCH4 ≤ 1% and cubic nanocrystalline WCy grains for fCH4> 1%.

Tunable SiO2 to SiOxCyH films by ozone assisted chemical vapor deposition from tetraethylorthosilicate and hexamethyldisilazane mixtures

Silica and silica-based materials with tunable functionalities are frequently encountered in low-k material applications, porous membranes, and microelectonic devices. In the present study, an innovative O2/O3 assisted CVD process for the deposition of such films at moderate temperature is presented, based on a dual precursor chemistry from hexamethyldisilazane (HMDS) and tetraethyl orthosilicate (TEOS). Films with tunable carbon content were obtained through variation of the HMDS flow ratio. A comprehensive FT-IR study reveals the transition of the material from a SiOxCyH type film containing -CH3 moieties, to a methyl-free SiOx film with the increase of the temperature. At the same time the water contact angle of 81.0° at 400 °C is decreased to 52.8° at 550 °C, related to the absence of methyl moieties in the latter. Ion beam analysis (IBA) confirms the lack of carbon in the films when deposition temperatures are equal to or exceed 500 °C. The resistance to liquid corrosion is investigated as a function of the deposition temperature; SiOx type films present a low Pliskin etching rate of 15 Å.s−1, with this value increasing to 60 Å.s−1 for the SiOxCy:CH3 films produced at the lower temperatures. It is found that the addition of HMDS to a TEOS chemistry can be utilized to modulate the film composition from SiOx to SiOxCyH and by such, tune the film functional properties, in particular its etching rate, opening the way to the development of new sacrificial films.

Characterization of historical minai and colorful luster glaze ceramics, using ionoluminescence technique

Some historical minai and colorful luster glaze ceramic samples were investigated by means of ionoluminescence technique. The complementary ion beam analysis techniques RBS and PIXE were employed to reveal their elemental compositions and depth profiles. The samples were discovered in the historical site of Tappeh Ghale in Iran, which dates back to 12th century. The ionoluminescence spectra of the samples reveal the strong dependence of the luminescence bands, mostly originating from oxygen-deficient centers, on the elemental compositions of the glaze samples. It is inferred that most of the luminescence centers likely have been created during the formation process of tin-opacified lead-rich glazes. The demonstrated capabilities of ionoluminescence in the current work, confirm the possibility of its application for fast and non-destructive characterization of historical glaze samples.

Perspectives for low energy reactions measurements at the new LEMA beam-line

Towards the end of 2017, a new beam line was commissioned at the Laboratorio Nacional de Espectrometría de Masas con Aceleradores (LEMA) at Instituto de Física of the Universidad Nacional Autónoma de México (IFUNAM). Initially, LEMA was a 1 MV tandetron accelerator just dedicated to Accelerator Mass Spectrometry (AMS); nowadays, the new line adopted the main characteristics of the AMS system in a natural way: i.e., it has a high precision measurement of the beam energy and a very high and stable current (tens of μ A) depending of charge state of each isotope. The precise low energy limit around 400 keV opens a window to study reactions in the region of interest for Astrophysics. At the same time, the LEMA beam-line allows to develop experiments combining nuclear reactions with AMS, as well the developing of all of kind of Ion Beam Analysis (IBA) studies. In this work the main characteristics of the line, the ancillary systems and the perspectives for low energy measurements for nuclear studies and applications are described.

Ion irradiation and modification: The role of coupled electronic and nuclear energy dissipation and subsequent nonequilibrium processes in materials

Understanding material responses to energy deposition from energetic charged particles is important for defect engineering, ion-beam processing, ion-beam analysis and modification, geologic aging, space exploration, and nuclear applications. As an incident ion penetrates a solid, its energy is transferred to electrons and to atomic nuclei of the solid. Much of this electronic energy deposition is subsequently transferred to the atomic structure via electron–phonon (e–ph) coupling, leading to local inelastic thermal spikes in which energy dissipation is influenced by the local environment. In addition, intense ionization can lead to high densities of localized electronic excitations in wide-bandgap materials and ceramics that can affect defect dynamics and atomic mobility. Specifically, energy exchange between electrons and atomic nuclei, along with localized electronic excitations, can lead to substantial competitive (ionization-induced annealing), additive (both electronic and nuclear energy depositions contributing to damage production), and synergistic (more damage than the sums of separate damage processes) effects. Although nonmonotonic effects of the e–ph coupling strength and athermal processes are demonstrated for pre-existing defects and residual damage during ion–solid interactions, there is limited understanding of when such electronic effects must be considered in atomic-scale models of damage production and evolution in a broad variety of materials. Complex ceramics and chemically disordered solid solution alloys with different constituent elements allow a systematic evaluation of defect dynamics and irradiation performance with increasing complexity. Current knowledge regarding tuning of bonding characteristics and chemical disorder to control atomic-level dynamics is reviewed. Although a lack of fundamental understanding obstructs the advancement of reliable predictions for ion beam material modification, it highlights challenges and opens research opportunities. Insights into the complex electronic and atomic correlations with extreme energy deposition will strengthen our ability to design materials and predict ion-irradiation-induced damage in a radiation environment, and they may pave the way to better control fundamental processes and design new material functionalities for advanced technologies.

High-resolution Rutherford backscattering spectrometry with an optimised solid-state detector

Rutherford Backscattering Spectrometry (RBS) is a powerful ion beam analysis technique in frequent use within materials science. The recent emergence of targets incorporating complex features such as ultra-scaled diffusion barriers and isotopically-enriched films has started to push the limits of the technique, necessitating the expanded use of systems with a higher energy resolution. The increased cost and complexity of these systems based on already well-established schemes may present a barrier to their more widespread adoption. Here, we present an RBS detection system specifically designed for simple integration into existing nuclear probe infrastructure, but with a considerably higher energy resolution than a standard passivated planar detector. We employ a modified silicon p–i–n photodiode integrated within an optimised in-vacuum preamplifier to achieve a relative energy resolution of 3 × 10−3 with 2.2 MeV He+ ions. In a glancing angle geometry, this corresponds to a depth resolution of ∼1.5nm and a mass resolution of <1u from light elements up to Cu. We demonstrate the use of this detector to measure the thermal diffusion of near-surface As implants in a Si substrate, important for the formation of ultra-shallow junctions; and the residual 29Si concentration in an isotopically enriched 28Si specimen, a promising platform for quantum computation.

Ion beam analysis of Li-Sn alloys for fusion applications

The use of liquid Li-Sn alloys for nuclear fusion applications may be hampered by the high melting point of Li-rich intermetallics. Aiming to inhibit their formation, the blend of pure Li (as high as 15 at.%) with pure Sn was controlled via mechanical alloying at room temperature under a dry Ar atmosphere. The depth profiling of Li down to depths near 15–20 μm was followed by nuclear reaction analysis, while elastic backscattering spectroscopy indicated the absence of O within the alloys. Elemental mapping using a nuclear microprobe evidenced the lateral spread of Li in the Sn matrix and identified Cr, Fe and Pb as the only contaminants with contents lower than 0.05 at.%. Despite the competing 2H(3He,p)4He, 6Li(3He,p)8Be, 7Li(3He,p)9Be and 7Li(3He,d)8Be nuclear reactions, retained amounts of deuterium in irradiated surfaces may be quantified with incident 3He+ ion beams in the 0.7 MeV–1.0 MeV energy range.

Time-Of-Flight ERDA for Depth Profiling of Light Elements

The time-of-flight elastic recoil detection analysis (TOF-ERDA) method is one of the ion beam analysis methods that is capable of analyzing light elements in a sample with excellent depth resolution. In this method, simultaneous measurements of recoil ion energy and time of flight are performed, and ion mass is evaluated. The energy of recoil ions is calculated from TOF, which gives better energy resolution than conventional Silicon semiconductor detectors (SSDs). TOF-ERDA is expected to be particularly applicable for the analysis of light elements in thin films. In this review, the principle of TOF-ERDA measurement and details of the measurement equipment along with the performance of the instrumentation, including depth resolution and measurement sensitivity, are described. Examples of TOF-ERDA analysis are presented with a focus on the results obtained from the measurement system developed by the author.

Field induced crossover in critical behaviour and direct measurement of the magnetocaloric properties of La0.4Pr0.3Ca0.1Sr0.2MnO3

La0.4Pr0.3Ca0.1Sr0.2MnO3 has been investigated as a potential candidate for room temperature magnetic refrigeration. Results from X-ray powder diffraction reveal an orthorhombic structure with Pnma space group. The electronic and chemical properties have been confirmed by X-ray photoelectron spectroscopy and ion-beam analysis. A second-order paramagnetic to ferromagnetic transition was observed near room temperature (289 K), with a mean-field like critical behaviour at low field and a tricritical mean-field like behaviour at high field. The field induced crossover in critical behaviour is a consequence of the system being close to a first-order magnetic transition in combination with a magnetic field induced suppression of local lattice distortions. The lattice distortions consist of interconnected and weakly distorted pairs of Mn-ions, where each pair shares an electron and a hole, dispersed by large Jahn–Teller distortions at Mn3+ lattice sites. A comparatively high value of the isothermal entropy-change (3.08 J/kg-K at 2 T) is observed and the direct measurements of the adiabatic temperature change reveal a temperature change of 1.5 K for a magnetic field change of 1.9 T.

Ion beam analysis (IBA) and instrumental neutron activation analysis (INAA) for forensic characterisation of authentic Viagra® and of sildenafil-based illegal products

Illegal trafficking of pharmaceutical products by criminal organisations is a global threat for public health. Drugs for erectile dysfunction such as phosphodiesterase type 5 inhibitors are the most commonly counterfeited medicines in Europe. The search of possible toxic chemical substances in seized products is needed to provide early warning for public health. Furthermore, the elemental profile of the seized products can be useful in criminal investigations. For the first time an ion beam analysis (IBA) procedure to characterise authentic Viagra® tablets and sildenafil-based illegal products is described. Moreover, results are compared with the ones obtained by instrumental neutron activation analysis (INAA) on authentic Viagra® tablets in two reactors. IBA results showed that a combination of particle-induced X-ray emission (PIXE) and secondary ion mass spectrometry using primary ions with energies in the range of several MeV (MeV-SIMS) is a powerful tool to characterise different products in a straightforward manner, allowing discrimination between legal and illegal products. INAA allowed accurate elemental quantification and also showed a great potential for the future implementation of an inter-laboratory classification system.