Ion beam technologies are today routine methods in electronic device manufacturing, e.g. the production of a modern processor needs 20-30 ion implantation steps. On the other hand, the 21st century is considered by many to be the century of light following a century of developments in electronics. Therefore, I will present several experiments for the manipulation of the optical properties of...
Type Ib diamonds containing ~200 ppm substitutional nitrogen were irradiated with 4.8 MeV/n swift heavy ions ($^{48}$Ca, $^{197}$Au, $^{238}$U) to investigate radiation-induced defect formation and evolution. A comprehensive spectroscopic approach combining on-line ionoluminescence, spatially resolved photoluminescence/Raman spectroscopy, UV/vis absorption, and infrared spectroscopy was...
The energy deposition of ions in water generates pressure waves. These ionoacoustic signals are commonly described within the thermoacoustic approximation, where localised heating and subsequent volume expansion are considered the primary sources of wave generation. According to this model, no pressure wave should be observed at 4 °C, a prediction confirmed in laser absorption experiments....
Low to medium energy ions in the keV regime have become a standard tool to tailor material properties, enable nanostructuring and analysis at the nanoscale. Yet, accessing the intrinsic ultrafast response of solids to a single ion impact has long been hindered by the difficulty of generating and precisely timing short, monoenergetic ion pulses in this energy regime. We present a synchronized...
Germanium is a material widely used in various applications, especially in optoelectronic devices, due to its excellent optical and electrical properties. In these devices, germanium is typically deposited in the form of thin films. Because of the mismatch in thermal expansion coefficients between the Ge film and the substrate, the material can develop either compressive or tensile stress that...
Ion bombardment is a powerful tool for tailoring the properties of materials, inducing structural modifications and enabling nanoscale analysis. However, understanding the fundamental response of matter to ion impact requires access to ultrafast processes that unfold on timescales ranging from femtoseconds to picoseconds. Although laser-based pump–probe techniques have long provided insight...
Ion impacts trigger atomic-scale processes in solids on ultrafast timescales, yet direct experimental access to these dynamics has been limited by the lack of short, monoenergetic ion pulses. To address these challenges, we developed a novel ion source based on strong-field photoionization of a cooled gas jet. In combination with a compact buncher system, we are able of generating...
As an air-stable Van der Waals magnetic semiconductor, CrSBr is receiving great research attention due to its exceptional optical, electronic, and magnetic properties. Below the Néel temperature of 132 K, CrSBr exhibits a typical A-type antiferromagnetic order comprised of antiferromagnetically coupled ferromagnetic monolayer. This special structure makes it susceptible to external stimuli,...
The controlled transport of ions through nanoconfined spaces has emerged as a crucial field with applications ranging from sensing to energy storage. Ion-track technology uses swift heavy ion irradiation to create tracks within the materials, and chemical etching to produce well-defined nanochannels with precisely tunable dimensions and geometries [1]. This attribute makes the channels...
The design of the Paris-Edinburgh Press (PEP) and large-volume diamond-anvil chambers (DAC) are designed to facilitate in-situ spectroscopic and optical measurements (e.g. Raman spectroscopy, optical observation) under high pressure and high temperature conditions, reaching up to 12 GPa and 1000 K. These setups accommodate sample sizes of 1x3mm. This setup is positioned on a motorized platform...
This work presents the synthesis and functional characterization of three-dimensional (3D) Au and Au–Ag alloy nanowire networks fabricated using ion-track nanotechnology. This approach allows precise control over nanowire diameter (40–200 nm), alloy composition (10–90% Ag), and network porosity (20-98%). Selective removal of Ag atoms yields hierarchical porous nanowires with tunable ligament...
This work presents detailed calculations of the Hamiltonian describing the combined magnetic dipole and non-axially symmetric electric quadrupole interactions. The resulting eigenvalues and eigenvectors are incorporated into the perturbation factor G22(t) for a polycrystalline sample, as defined by time-differential perturbed angular correlation (TDPAC) theory. G22(t) spectra for the combined...
Swift heavy ions (SHIs) are high-mass ions with high kinetic energies in the MeV–GeV range produced by large accelerator facilities. Upon traversing a material, SHIs induce various physical and chemical effects within the material, including extended defects, phase transitions, amorphization, or chemical reactions. The combination of high pressure and heavy ions is anticipated to induce...
Swift heavy ion irradiation is a powerful tool in materials research, particularly in terms of materials modification and engineering. In combination with chemical track etching and electrochemical deposition, swift heavy ion beams can be employed to synthesize high aspect ratio nanowires. This approach enables systematic investigations of size-dependent properties of nanowires, due to...
At the nanoscale metals exhibit catalytic properties that differ from those in the bulk phase. Gold, which is commonly regarded as inert, becomes a powerful catalyst for reactions such as the water gas shift reaction, which is an important step in the production of hydrogen. The catalytic activity depends on the size and shape of the metallic nanoparticle.
We explore the shaping of...
Recently, we applied evolutionary optimization, namely differential evolution, to fit Rutherford backscattering spectra [1]. We derived an algorithm that is capable of finding, with very high precision, the sample composition profile that best fits the experimental spectra in an autonomous manner. The robust nature of the differential evolution algorithm, especially with respect to the rather...
Due to growing technological and scientific interest in radiation effects on various nanomaterials, this work studies the impact of heavy ions on bismuth nanowires (NWs) using molecular dynamics simulations (MD) with “thermal spike” approximation to emulate the high-temperature zone generated by electronic excitation along the ion track. The diameter of the bismuth nanowires was...
Group-IV superconducting semiconductors present promising opportunities on the development of scalable hybrid platforms for quantum devices. However, achieving superconducting states in semiconductors remains challenging, particularly concerning the origin of coherent coupling and the relationship between carrier concentration and critical temperature. In this study, ion implantation and...
The influence of swift heavy ion radiation on nanostructures has attracted increasing interest in recent years. To systematically explore size-effects on the interaction of swift heavy ions with nanowires, we have synthesized Bi nanowires with tailored diameter between 20 and 400 nm by electrodeposition in etched ion track membranes. These nanowires were irradiated at the GSI linear...
The General Low Mass (GLM) beamline of ISOLDE is dedicated to collecting and handling radioactive isotopes.
The currently still used ion implantation chamber is a single vacuum chamber equipped with a turbo pump capable of reaching 1E-5 mbar, often relying on the beamline vacuum pump to achieve its optimal pressure of 1E-6 mbar.
The new ion implantation chamber features a load-lock...
In recent years, two-dimensional (2D) materials and the ion-induced, tailored modification of their structural, optical and electronic properties have attracted increasing attention, driven by the potential application of modified 2D materials in optics and microelectronics. Raman spectroscopy is an established tool to characterize such ion-induced modifications, especially changes in the...
The doping of two-dimensional (2D) transition metal dichalcogenides (TMDCs) by an approach compatible with circuit integration is crucial. However, ion implantation, the most commonly used method for doping semiconductors, poses significant challenges for 2D-TMDCs because of the requirement for ultra-low ion energy and the difficulty of restoring damaged 2D materials. Here, we achieve bipolar...
Ions penetrating matter cause a number of different electronic excitations in the material and in the projectile itself. The investigation of ion induced photon emission contributes to a better understanding of the exact processes taking place. We investigate the photons emitted upon transmission of keV He and Ne ions through thin single-crystalline Si membranes. The measurements were recorded...
Recent developments of keV and MeV ion beam analytical tools for in-situ and in-operando characterization of a number of material systems with high relevance for energy-related applications will be presented. The ion-beam based characterization was complemented by atom probe tomography, X-ray diffraction and transmission electron microscopy.
We performed high-resolution depth profiling of...
The inelastic thermal spike model${}^1$ has been widely used to describe the effects of swift heavy ions, but its theoretical suitability remains under debate${}^2$. The parameters for the underlying mathematical equations, the so called two-temperature model (TTM) equations, are typically obtained from empirical fits to ion track radii. Recent computational advances now make it possible to...
Exploring the structural response and property transformations of materials under combined extreme conditions holds enormous importance across diverse, multidisciplinary, and fundamental research domains. The application of extreme pressures can induce novel phases and structures with distinctive properties. In this project, we explore the effects of exposing materials to high pressures...
ISOLDE-CERN is the worldwide reference facility for the production and delivery of radioactive ion beams of high purity. Since the late 70s the laboratory is pioneer in the use of nuclear techniques for studying local properties of materials using high-technology equipment [1]. For instance, the brand-new ultra-high-vacuum implantation chamber called ASPIC’s Ion Implantation chamber (ASCII)...
With its unique combination of an external magnetic field of up to 8.5 tesla and the ability to heat and cool samples during measurements, the MULTIPAC Time-Differential Perturbed Angular Correlation (TDPAC) setup creates new possibilities for studying materials and their phase transitions. Building on this advanced instrumentation, the dedicated control and analysis software PACBIT enables...
It is still an open question whether magnetoelectric coupling occurs at the atomic scale in multiferroic BiFeO3. Nuclear solid-state techniques monitor local fields at the atomic scale. Using such an approach, we show that, contrary to our own expectation, ferroelectric and magnetic ordering in bismuth ferrite (BiFeO3 or BFO) decouple at the unit-cell level. Time differential perturbed angular...
Cancer is one of the main causes of death worldwide, and radiotherapy (RT) is one of the prominent modalities in the fight against it. From a biological perspective, the main target of RT is the DNA of cancer cells due to its radiosensitivity. To conduct fundamental research into radiation effects at sub-cellular scales, highly precise cell irradiation with micrometer- and nanometer-sized...
Proton minibeam radiotherapy (pMBT) is a novel radiotherapy method that deploys proton beams, combined with spatial fractionation, intending to broaden the therapeutic window while protecting healthy tissues. Preclinical studies have already highlighted the potential of pMBT in sparing healthy tissues and achieving better tumor control compared to conventional proton therapy. Constructing a...
Accelerator Mass Spectrometry (AMS) has long been established as a prime technique to measure an array of long-lived radionuclides in the environment. Radiocarbon has been established first, and later the method has been expanded to include $^{10}$Be, $^{26}$Al, and $^{129}$I, to name but a few. The method originally developed on large nuclear physics tandem accelerators with terminal voltages...
Accelerator Mass Spectrometry (AMS) is an ultrasensitive method for detection of naturally or anthropogenically produced long-lived radionuclides in our environment.
To combine this method with the capabilities of a secondary-ion mass spectrometer (SIMS: IMS 7f-Auto from Cameca) is challenging. The idea is to use the micron-scale spatial resolution of the SIMS and the high selectivity through...
The Apparatus for Surface Physics and Interfaces at CERN (ASPIC) has been installed in the solid state physics part of the ISOLDE experimental hall. Operating at ultra-high vacuum (UHV $\leq 10^{-8}$mbar) ASPIC's versatility was used to study metallic surfaces, the magnetic behavior of thin films and an interface evolution, as well as employing radioactive isotopes and a variety of surface...
The interaction of swift heavy ions (SHI) with organic matter is highly relevant for applications such as cancer therapy and the development of biomaterials based on SHI irradiation. Furthermore, the interaction of SHI with complex molecular systems such as biomolecules is interesting from a fundamental point of view in terms of the excitation mechanisms involved and how the energy deposited...
