10 MeV proton-irradiation effects on a YBCO-based test structure were analyzed by measuring its current-voltage (IV) characteristics for different cumulated fluences. For fluences of up to $\sim$80$\cdot$10$^9$~p/cm$^2$ no changes in the electrical behavior of the device were observed, while for a fluence of $\sim$~300$\cdot$10$^9~$ p/cm$^2$ it becomes less conducting. A detailed analysis of the room temperature IV characteristics based on the $γ$ power exponent parameter [$γ=dLn(I)/dLn(V)$] allowed us to reveal the main conduction mechanisms as well as to establish the equivalent circuit model of the device. The changes produced in the electrical behavior, in accordance with Monte Carlo TRIM simulations, suggest that the main effect induced by protons is the displacement of oxygen atoms within the YBCO lattice, particularly from oxygen-rich to oxygen-poor areas, where they become trapped.
The defect-rich morphology of YBa$_{2}$Cu$_{3}$O$_{7-δ}$ (YBCO) thin films leads to a glass-like arrangement of Abrikosov vortices which causes the resistance to disappear in vanishing current densities. This vortex glass consists of entangled vortex lines and is identified by a characteristic scaling of the voltage-current isotherms. Randomly distributed columnar defects stratify the vortex lines and lead to a Bose glass. Here, we report on the observation of an ordered Bose glass in a YBCO thin film with a hexagonal array of columnar defects with 30 nm spacings. The periodic pinning landscap…
The effects of ionizing radiation on materials often reduce to "bad news." Radiation damage usually leads to detrimental effects such as embrittlement, accelerated creep, phase instability, and radiation-altered corrosion. This last point merits special attention. Elucidating synergies between radiation and corrosion has been one of the most challenging tasks impeding the deployment of advanced reactors, stemming from the combined effects of high temperature, corrosive coolants, and intense particle fluxes. Here we report that proton irradiation significantly and repeatably decelerates intergr…
We report on the effect of electron and proton irradiation on effective minority carrier lifetimes ($τ_{eff}$) in p-type Ge wafers. Minority carrier lifetimes are assessed using the microwave-detected photoconductance decay ($μ$W-PCD) method. We examine the dependence of $τ_{eff}$ on the p-type doping level and on electron and proton radiation fluences at 1 MeV. The measured $τ_{eff}$ before and after irradiation are used to estimate the minority carriers diffusion lengths, which is an important parameter for solar cell operation. We observe $τ_{eff}$ ranging from 50 to 230 $μ$s for Ge doping …
The bulk irradiation of materials with 10-30 MeV protons promises to advance the study of radiation damage for fission and fusion power plants. Intermediate energy proton beams can now be dedicated to materials irradiation within university-scale laboratories. This paper describes the first such facility, with an Ionetix ION-12SC cyclotron producing 12 MeV proton beams. Samples are mm-scale tensile specimens with thicknesses up to 300 um, mounted to a cooled beam target with control over temperature. A specialized tensile tester for radioactive specimens at high temperature (500+ °C) and/or va…
Tailoring the properties of YBa$_{2}$Cu$_{3}$O$_{7-δ}$ thin films by 30 keV He$^+$ irradiation: An enabling route to superconducting device nanopatterning
University of Vienna（维也纳大学）；Universität Tübingen, Physikalisches Institut, Center for Quantum Science (CQ) and LISA +（蒂宾根大学物理学院，量子科学中心（CQ）和LISA+）
The electrical and structural characteristics of 50 nm zinc oxide (ZnO) metal-semiconductor-metal (MSM) ultraviolet (UV) photodetectors subjected to proton irradiation at different temperatures are reported and compared. We irradiated the devices with 200 keV protons to a fluence of 1016 cm-2. Examination of the X-ray diffraction (XRD) rocking curves indicates a strongly preferred (100) orientation for the grains of the as-deposited film, with decreases in crystal quality for all irradiated samples. In addition, peak shifts in XRD and Raman spectra of the control sample relative to well-known …
Fusion and advanced fission power plants require advanced nuclear materials to function under new, extreme environments. Understanding the evolution of mechanical and functional properties during radiation damage is essential to the design and commercial deployment of these systems. The shortcomings of existing methods could be addressed by a new technique - intermediate energy proton irradiation (IEPI) - using beams of 10 - 30 MeV protons to rapidly and uniformly damage bulk material specimens before direct testing of engineering properties. IEPI is shown to achieve high fidelity to fusion an…
Proton radiation damage is an important failure mechanism for electronic devices in near-Earth orbits, deep space and high energy physics facilities. Protons can cause ionizing damage and atomic displacements, resulting in device degradation and malfunction. Shielding of electronics increases the weight and cost of the systems but does not eliminate destructive single events produced by energetic protons. Modern electronics based on semiconductors - even those specially designed for radiation hardness - remain highly susceptible to proton damage. Here we demonstrate that room temperature (RT) …
Van der Waals (vdWs) crystals have attracted a great deal of scientific attention due to their interesting physical properties and widespread practical applications. Among all, CrSiTe3 (CST) is a ferromagnetic semiconductor with the Curie temperature (TC) of ~32 K. In this letter, we study the magnetic properties of bulk CST single-crystal upon proton irradiation with the fluence of 1x1018 protons/cm2. Most significantly, we observed an enhancement (23%) in the saturation magnetization from 3.9 μB to 4.8 μB and is accompanied by an increase in the coercive field (465-542 Oe) upon proton irradi…
Proton irradiation of both n-type and semi-insulating bulk samples of \b{eta}-Ga2O3 leads to the formation of one paramagnetic defect with spin S=1/2, monoclinic point symmetry, a g-tensor with principal values of gb=2.0313, gc=2.0079, ga*= 2.0025 and quasi isotropic superhyperfine interaction of 13G with two equivalent Ga neigbours. Its high introduction rate indicates it to be a primary irradiation induced defect. At low temperature, photoexcitation transforms this defect into a different metastable S=1/2 center with principal g-values of gb=2.0064, gc=2.0464, ga*= 2.0024 and a reduced hyper…
In this letter, we report the effects of irradiating hydrogen-terminated diamond surfaces with protons. We study the electrical behavior of the two-dimensional hole gas that forms on the diamond surface as a result of hydrogen-termination. Four diamond samples, two of which were passivated with Al2O3 and the other two unpassivated, were irradiated with 2 MeV protons at two fluences, 0.5x10^14 and 1.0x10^14 /cm^2. The hole conductivity degraded at a higher proton fluence, which is attributed to the reduction of the mobility caused by enhanced hole scattering. Both passivated and unpassivated sa…
Modern electronic devices utilize charge to transmit and store information. This leaves the information susceptible to external influences, such as radiation, that can introduce short timescale charge fluctuations and, long term, degrade electronic properties. Encoding information as spin polarizations offers an attractive alternative to electronic logic that should be robust to randomly polarized transient radiation effects. As a preliminary step towards radiation-resistant spintronic devices, we measure the spin properties of n-GaAs as a function of radiation fluence using time-resolved Kerr…
We examine the magnetic properties of the quasi 2D ferrimagnetic single crystal Mn3Si2Te6 (MST) through critical phenomena and magnetic entropy analysis in the easy axis (H || ab) as a function of proton irradiance. Employing a modified asymptotic analysis method, we find that upon proton irradiation the critical exponents do not fall into any particular universality class but lie close to mean field critical exponents (γ = 1, \b{eta} = 0.5). The presence of long-range interactions can be safely assumed for the pristine and irradiated cases of MST examined in this work. Further analysis on the…
We report the magnetic response of high purity type IIa single crystal CVD diamond following high energy irradiation by 2.2 MeV proton micro-beams, produced using Nuclear Microprobe techniques. Post-irradiation microanalysis is achieved using Atomic Force, Magnetic Force and Electrostatic Force Microscopy (AFM, MFM & EFM) as well as Raman spectroscopy. Comparison between MFM and EFM measurements at zero electrical bias is used to preclude artefacts of electrostatic origin suggesting the presence of magnetic states in the microscale regions induced by proton micro-irradiation. Analysis of the i…
The discovery of long-range magnetic ordering in atomically thin materials catapulted the van der Waals (vdW) family of compounds into an unprecedented popularity. In particular, with a current push in space exploration, it is beneficial to study how the properties of such materials evolve under proton irradiation. Owing to their robust intra-layer stability and sensitivity to external perturbations, these materials provide excellent opportunities for studying proton irradiation as a non-destructive tool for controlling their magnetic properties. Specifically, the exfoliable Cr2Si2Te6 (CST) is…
Ion irradiation provides a promising substitute to neutron tests for investigating the effects of radiation on materials for fission and fusion reactor plants. Here we show proton irradiation can quantitatively reproduce precipitation that leads to embrittlement in reactor pressure vessel steels, at dose rates 10,000 times greater than experienced in fission reactor operation. Small-angle neutron scattering (SANS) is used to characterize precipitate size distributions in copper-containing steels irradiated to average doses of approx. 7 mdpa with 5 MeV protons. Comparing our results with the li…
The development of defect populations after proton irradiation of n-type 4H-SiC and subsequent annealing experiments is studied by means of deep level transient (DLTS) and photoluminescence (PL) spectroscopy. A comprehensive model is suggested describing the evolution and interconversion of irradiation-induced point defects during annealing below 1000°C. The model proposes the EH4 and EH5 traps frequently found by DLTS to originate from the (+/0) charge transition level belonging to different configurations of the carbon antisite-carbon vacancy (CAV) complex. Furthermore, we show that the tran…
Unlike the vast amount of irradiated material data that exists for stainless steel internals from LWRs, with high fast neutron flux and an irradiation temperature of~330oC, the CANDU reactor is unique with a high thermal spectrum stainless steel components peripheral to the core. In particular, the CANDU design contains an austenitic stainless steel calandria vessel, which contains the heavy water moderator at a temperature of 60-80oC. This article explores the effects of low (60-80oC) and moderate (300-360oC) irradiation temperature on irradiation induced defects and defect sinks, both in ter…
Many astrochemical models today explicitly consider the species that comprise the bulk of interstellar dust grain ice-mantles separately from those in the top few monolayers. Bombardment of these ices by ionizing radiation - whether in the form of cosmic rays, stellar winds, or radionuclide emission - represents an astrochemically viable means of driving a rich chemistry even in the bulk of the ice-mantle, now supported by a large body of work in laboratory astrophysics. In this study, using an existing rate equation-based astrochemical code modified to include a method of considering radiatio…
Traditionally, it has been assumed that the stopping of a swift ion travelling through matter can be understood in terms of two essentially independent components, i.e. electronic vs. nuclear. Performing extensive Ehrenfest MD simulations of the process of proton irradiation of water ice that accurately describe not only the non-adiabatic dynamics of the electrons but also of the nuclei, we have found a stopping mechanism involving the interplay of the electronic and nuclear subsystems. This effect, which consists in a kinetic energy transfer from the projectile to the target nuclei thanks to …
