Maximum Vacancy Research Articles

The effect of micromechanical stresses on vacancy formation and stress-driven mass-transport in polycrystalline Fe–Au alloy

In recent years, a new class of super saturated binary and ternary alloys have demonstrated the ability for the self-healing of creep-induced voids formed at the grain boundaries. However, a clear understanding of the parameters affecting the self-healing mechanism is still not yet complete. One of the main challenges is understanding the effect of microstructure and micromechanical stresses on the redistribution of the healing-solute and vacancies. To this end, we address this issue using a CALPHAD-informed diffusion model coupled with crystal plasticity. In principle, the approach is general and can be used for any binary Fe–X alloy, but in this work Fe–Au binary system is used since it experimentally showed the best healing efficiency. First, we present a multicomponent diffusion model considering cross and stress-driven diffusion. The effect of stress was also considered on the equilibrium vacancy concentration. To investigate the effect of the micromechanical stresses, a representative volume element (RVE) was obtained using the phase-field method. The results showed that the maximum vacancy concentration is at the grain boundaries (GBs) with the highest hydrostatic tensile stresses. These were also the regions of the highest Au enrichment. A crucial factor to achieve this is the high diffusivity of Au compared to the Fe matrix. Increasing the stresses, lead to an increase both in vacancy and Au concentration. The accompanying increased stress triaxiality is suggested to be the reason for the reduced self-healing efficiency observed in previous experimental studies.

Enhanced photocatalytic activity in BaBi4Ti4O15 with excess Bi2O3

The photocatalytic activity of BaBi4Ti4O15 with excess bismuth oxide (0–10 wt%) and the parametric study of photocatalysis are investigated in this article. BaBi4Ti4O15 with excess bismuth oxide was synthesized via a solid-state route followed by calcination at 950 °C for 4 h. All BaBi4Ti4O15 samples were characterized by X-ray diffractometer, scanning electron microscopy, energy dispersive X-ray spectroscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, and direct optical bandgap. Synthesized BaBi4Ti4O15 with excess bismuth oxide has an orthorhombic perovskite crystal structure with A21am space group. Excess bismuth varies in the concentration of oxygen vacancies, and 8 wt% excess BaBi4Ti4O15 has maximum oxygen vacancy. Excess bismuth also changes direct bandgap; the lowest bandgap is 2.33 eV for 8 wt% excess bismuth. The photocatalytic activity of BaBi4Ti4O15 with excess bismuth oxide (0–10 wt%) showed that 8 wt% excess bismuth has the highest photocatalytic activity. The parametric study of photocatalysis used the initial concentration, volume, and light source intensity as variables. The parametric study suggested that initial concentration, intensity, and volume were correlated with the degradation rate. Indoor dye cleaning in normal room light was also tested for real-life demonstration. BaBi4Ti4O15 was also characterized by an X-ray diffractometer and X-ray photoelectron spectroscopy to investigate the effect of photocatalysis.

Cerium doped Co/AC catalysts for higher alcohols synthesis from syngas

Higher alcohols synthesis (HAS) from CO hydrogenation has attracted a considerable attention owing to their utilization in fuels and chemical intermediates. However, it is still very difficult to improve the selectivity of higher alcohols via the Fischer-Tropsch process. Based on the understanding of the current research progress, in the present work, a series of the Ce doped activated carbon loaded Co catalysts were prepared and characterized by XRD, XPS, N2 adsorption-desorption, H2-TPR, and CO2-TPD-MS etc. It was found that there is a linearly positive correlation between the selectivity of total alcohols and oxygen vacancies, so the improvement of the selectivity to total alcohols can be achieved by increasing the number of oxygen vacancies on the catalyst surface. The Co-7.5Ce/AC catalyst showed the maximum oxygen vacancy ratio (46.5%), exhibiting the best total alcohols selectivity (23.5%). This work revealed the roles of oxygen vacancies in the synthesis of higher alcohols from syngas and provided a new idea for the development of Co-based catalysts for the process.

Oxygen vacancy luminescence and band gap narrowing driven by Ce ion doping with variable valence in SnO2 nanocrystals

Although considerable research works have witnessed the important modulations of oxygen vacancies on the optical, electrical, and magnetic properties of SnO2 nanostructures, it is not easy to control oxygen vacancy defects in such systems.The difficulty stems from that oxygen vacancy is a kind of atomic defect, and its distribution is sensitive to process conditions and external factors, which makes direct characterization and purposeful control difficult. The purpose of this work on Ce-doped SnO2 nanocrystals is to investigate the tolerance of the host lattice to Ce ions, the population and evolution of Ce3+/Ce4+ ions, and the possibility to adjust oxygen vacancies by Ce3+ ions, and then focus on the influence of oxygen vacancy defects on the band gap and luminescence performance. As Ce doping concentration increases from 0 to 12 at.%, the doped system changes from Ce3+ dominated at low doping amount (≤3 at.%) to Ce3+/Ce4+ coexistence at medium doping concentration (3 at.% ∼ 9 at.%), to occurrence of CeO2 impurity phase at over doping (∼12 at.%). The optimum doping occurs at 6 at.%, which corresponds to the saturated critical point of Ce3+ content and the maximum oxygen vacancy concentration. Importantly, the oxygen vacancies in the current Ce-doped SnO2 nanocrystals is directly regulated by the Ce3+ ion concentration on the Sn sites, which plays an important role in the band gap tuning and visible light emission. With Ce concentration increasing from 0 to 12 at.%, the band gap monotonicity decreases from 3.36 eV to 3.12 eV, while the intensity of the oxygen vacancy luminescence band first increases and then decreases, with the turning point at 6 at.%. Both band gap narrowing effect and enhanced emission indicate that Ce-doped SnO2 should be a promising method to design and manufacture visible light responsive SnO2 based optoelectronic materials by manipulating oxygen vacancy defects.

Engineering of oxygen vacancy defect in CeO2 through Mn doping for toluene catalytic oxidation at low temperature

Catalytic oxidation is considered a highly effective method for the elimination of volatile organic compounds. Oxygen vacancy defect engineering in a catalyst is considered an effective approach for high-performance catalysts. Herein, a series of doped MnxCe1-xO2 catalysts (x = 0.05–0.2) with oxygen vacancy defects were synthesized by doping low-valent Mn in a CeO2 lattice. Different characterization techniques were utilized to inspect the effect of doping on oxygen vacancy defect generation. The characterization results revealed that the Mn0.15Ce0.85O2 catalyst has the maximum oxygen vacancy concentration, leading to increased active oxygen species and enhanced oxygen mobility. Thus, Mn0.15Ce0.85O2 catalyst showed an excellent toluene oxidation activity with 90% toluene conversion temperature (T90) of 197 °C at a weight hourly space velocity of 40,000 mL g−1 h−1 as compared to undoped CeO2 (T90 = 225 °C) and Ce based oxides in previous reports. In addition, the Mn0.15Ce0.85O2 catalyst displayed strong recyclability, water resistant ability and long-time stability. The in situ DRIFT results showed that the Mn0.15Ce0.85O2 catalyst has a robust oxidation capability as toluene is quickly adsorbed and actuated as compared to CeO2. Thus, the present work lays the foundation for designing a highly active catalyst for toluene elimination from the environment.

Monte Carlo simulation of vacancies produced in lead-free piezo-ceramics by X-ray radiation damage

This work presents the results of a simulation by the Monte Carlo method, performed through the GEANT4 code, of the irradiation and energy deposition by high flux X-rays on the piezoelectric ceramic Bismuth-Sodium Titanate doped with Barium. X-rays energies were around the Ti-K absorption edge emulating a transmission experiment, and the irradiation with 5300 eV X-rays for a fluorescence experiment. The method consists of introducing the data that describes a characteristic R3c structure of the polarized ceramic, reported in the literature. The absorption coefficients for the energies of interest, as well as the energy deposited in the form of radiation doses, are calculated. Intensity changes for specific energy lines in the micro-fluorescence spectra, which suggest the presence of vacancies in the crystal structure, are verified via simulation. The vacancy density produced by a typical photon flux of a fourth-generation synchrotron beam is calculated through the threshold displacement energy for vacancy production. Consequently, the simulation is carried out for a structure with appropriate Bi and O vacancies, and the ability to detect the radiation damage is verified by comparison with micro-XRF and XAFS experimental results. The simulation predicts a maximum dose of 1.21-1.27x105 Gy irradiating 107 photons for the given energy and a maximum vacancy density of 1.10x108 / micron3 for oxygen atoms and 6.90x107 /micron3 for bismuth atoms.

The structural, magnetic and electrical transport properties of perovskite La0.67Sr0.33Mn1−x(VMn)xO3: The B-sites vacancies as a rapier

The polycrystalline samples of manganites perovskite [Formula: see text] with B-sites vacancies were synthesized using the conventional solid-state reaction method. The results based on the X-Ray Diffraction (XRD) and Scanning Electron Microscope (SEM) analyses show that the samples with [Formula: see text] have a secondary phase of lanthanum oxides. It indicates there is a maximum vacancy content at the B-sites with [Formula: see text]. By X-ray Photoelectron Spectra (XPS), the ionicities of oxygen were determined to be 0.762, 0.842, and 0.886, corresponding to [Formula: see text], 0.03, and 0.05, respectively. The B-sites vacancy plays an important role in magnetic performances: (i) B-sites vacancy changes the contents and the average cant angle of Mn cations, and makes the specific saturation magnetization at 100 K and 300 K increase, and then decrease rapidly. (ii) The Curie temperature changes in a small range from 363.93 K to 366.00 K, resulting from both the double exchange interaction increasing and the double exchange path destroyed by the vacancies. (iii) The magnetoresistance (MR) at room temperature achieves 6.97% in the [Formula: see text] sample, whose value is larger than that of [Formula: see text] sample.

Machine Learning-Based Algorithm for Channel Selection Utilizing Preemptive Resume Priority in Cognitive Radio Networks Validated by NS-2

This paper utilizes the cognitive radio (CR) spectrum to the fullest extent for extended applications requiring discretion. The CR technology provides various supports for cognitive radio networks (CRNs). The latter has CR nodes that sense free channels. Then, the CRN allocates the unused channels to secondary users (SUs) or unlicensed users. This allocation is termed the spectrum handoff. In this paper, by considering the identical channels in CR networks, a novel machine learning algorithm (the support vector machine—SVM) is employed. In addition, the queuing model of the preemptive resume priority M/M/1 is used. The proposed spectrum handoff algorithm selects the best possible CR network channel. The spectrum handoff algorithm uses the stated SVM algorithm scheme, which covers the transmitted and received power, the minimum service time, the data rate and the maximum vacancy time for the SU, to attain the maximum throughput. However, in multi-user greedy channel selection (GCS), only two parameters are considered. The proposed spectrum handoff algorithm based on the SVM scheme enhances the performance, and the SU throughput is improved to 68.7%. This approach is better than the GCS channel selection scheme. Additionally, this approach decreases the number of spectrum handoffs. As a result, the training accuracy of the SVM method is 97.6%, and it outperforms conventional methods.

Impact of defect-driven surface inhomogeneity and minimal island formation on temperature-programmed desorption spectra: A kinetic Monte Carlo study

Inhomogeneity often manifests itself on surfaces with pre-adsorbed adsorbates in which islands have widely-disparate sizes due to the presence of distinct morphological features or perhaps even impurities, or defects. In this kinetic Monte Carlo study, we developed a model in which these defects are in the form of vacancy clusters or chains and grow progressively longer with each repeated adsorption-desorption cycle owing to repeated stress that a substrate is subjected to with each cycle. We then explored different simulation-imposed conditions – vacancy or defect concentration as well as maximum vacancy chain length – and noted their impact on the resulting temperature-programmed desorption spectra. We found that growing chains can induce single desorption peak to progressively shift, then split into two closely-overlapping ones over a course of several such cycles. Interestingly, such evolving peaks may hide the true desorption kinetics since calculation of desorption order may yield unconventional, non-integer values – neither zero, first or second-order. We also observed that for the same vacancy concentration, peak-splitting becomes more pronounced with increasing maximum chain length. Analysis of simulation data also revealed that unlike bigger and more compact islands, small ones follow first-order desorption kinetics rather than half-order kinetics.

Precipitates and voids in cubic silicon carbide implanted with 25Mg+ ions

Single crystal cubic phase silicon carbide (3C-SiC) films on Si were implanted to 9.6 × 101625Mg+/cm2 at 673 K and annealed at 1073 and 1573 K for 2, 6, and 12 h in an Ar environment. The data from scanning transmission election microscopy (STEM) and electron energy loss spectroscopy (EELS) mapping suggest a possible formation of unidirectionally aligned tetrahedral precipitates of core (MgC2)-shell (Mg2Si) in the implanted sample annealed at 1573 K for 12 h. There are also small spherical voids near the surface and larger faceted voids around the region of maximum vacancy concentration. Atom probe tomography confirms 25Mg segregation dominated by small atomic clusters with local 25Mg concentrations up to 85 at.%. The resulting precipitate size and number density are found to decrease and increase, respectively, probably as a result of the thermal annealing that decomposes the 25Mg-bearing precipitates at the elevated temperatures and subsequent nucleation and growth below 1073 K during the cooling stage. The results from this study provide data needed to fully understand the property degradation of SiC in a high-flux fast neutron environment.

H2O splitting via a two-step solar thermoelectrolytic cycle based on non-stoichiometric ceria redox reactions: Thermodynamic analysis

H2 production via a novel two-step solar thermoelectrolytic cycle based on non-stoichiometric ceria reduction/oxidation reactions is thermodynamically analyzed. The two-step cycle encompasses (1) the solar thermoelectrolytic reduction of ceria using a combination of concentrated solar irradiation, reduced partial pressure, and electricity from a photovoltaic array to increase the oxygen vacancy concentration in the sublattice and (2) the non-solar oxidation of non-stoichiometric ceria with H2O to produce H2, or CO2 to produce CO. The re-oxidized ceria is returned to the first step to complete the cycle. A thermodynamic analysis that imposes first and second law constraints to determine optimal performance predicts a solar-to-fuel efficiency of 31.1% for a reduction temperature of 1424 K and a maximum oxygen vacancy concentration of 0.229.

Choosing among heterogeneous server clouds

This paper considers a model of interest in cloud computing applications. We consider a multiserver system consisting of N heterogeneous servers. The servers are categorized into M($$\ll N$$źN) different types according to their service capabilities. Jobs having specific resource requirements arrive at the system according to a Poisson process with rate $$N \lambda $$Nź. Upon each arrival, a small number of servers are sampled uniformly at random from each server type. The job is then routed to the sampled server with maximum vacancy per server capacity. If a job cannot obtain the required amount of resources from the server to which it is assigned, then the job is discarded. We analyze the system in the limit as $$N \rightarrow \infty $$Nźź. This gives rise to a mean field, which we show has a unique fixed point and is globally attractive. Furthermore, as $$N\rightarrow \infty $$Nźź, the servers behave independently. The stationary tail probabilities of server occupancies are obtained from the stationary solution of the mean field. Numerical results suggest that the proposed scheme significantly reduces the average blocking probability compared to static schemes that probabilistically route jobs to servers in proportion to the number of servers of each type. Moreover, the reduction in blocking holds even for systems at high load. For the limiting system in statistical equilibrium, our simulation results indicate that the occupancy distribution is insensitive to the holding time distribution and only depends on its mean.

Oxygen interstitial and vacancy conduction in symmetric Ln2 ± x Zr2 ± x O7 ± x/2 (Ln = Nd, Sm) solid solutions

We have compared (Ln 2- x Zr x )Zr 2 O 7 + x/2 (Ln = Nd, Sm) pyrochlorelike solid solutions with interstitial oxide ion conduction and Ln2(Zr 2- xLnx)O 7- δ (Ln = Nd, Sm) pyrochlorelike solid solutions with vacancymediated oxide ion conduction in the symmetric systems Nd2O3-ZrO2 (NdZrO) and Sm2O3- ZrO2 (SmZrO). We have studied their structure, microstructure, and transport properties and determined the excess oxygen content of the (Sm 2- xZrx)Zr2O7 + x/2 (x = 0.2) material using thermal analysis and mass spec� trometry in a reducing atmosphere (H 2 /Ar-He). The Ln 2 ± x Zr 2 ± x O 7 ± x/2 (Ln = Nd, Sm) solid solutions have almost identical maximum oxygen vacancy and interstitial conductivities: (3-4) × 10 -3 S/cm at 750°C. The lower oxygen vacancy conductivity of the Ln2(Zr 2- xLnx)O 7- δ (Ln = Nd, Sm; 0 < x ≤ 0.3) solid solutions is due to the sharp decrease in it as a result of defect association processes, whereas the interstitial oxide ion con� ductivity of the (Ln 2- xZrx)Zr2O 7+ x/2 (Ln = Nd, Sm; 0.2 ≤ x < 0.48) pyrochlorelike solid solutions is essen� tially constant in a broad range of Ln 2 O 3 concentrations.

Enhanced photocatalytic activity of Mg0.05Zn0.95O thin films prepared by sol–gel method through a cycle

Mg0.05Zn0.95O thin films were prepared on silicon substrates by a sol–gel dip-coating technique. Microstructure, surface topography and optical properties of the thin films were characterized by X-ray diffraction, atom force microscopy, Fourier transform infrared spectrophotometer and fluorescence spectrometer. The results show that the thin film annealed at 700 °C has the largest average grain size and exhibits the best c-axis preferred orientation. As annealing temperature increases to 800 °C, the grain along c-axis has been suppressed. Roughness factor and average particle size increase with the increase of annealing temperature. The IR absorption peak appearing at about 416 cm−1 is assigned to hexagonal wurtzite ZnO. The thin film annealed at 700 °C has the maximum oxygen vacancy, which can be inferred from the green emission intensity. Photocatalytic results show that the thin film annealed at 700 °C exhibits remarkable photocatalytic activity, which may be attributed to the larger grain size, roughness factor and concentration of oxygen vacancy. Enhanced photocatalytic activity of Mg0.05Zn0.95O thin films after a cycle may be attributed to the increase of surface oxygen vacancy and photocorrosion of amorphous MgO on the surface of thin film under UV irradiation.

Simple Rules Imposed on a Primitive Cubic Lattice Robustly Generate Structures that Mimic Features of Real Proteins

We introduce a set of simple and well-defined rules, which produce protein-like networks when they are imposed on a primitive cubic lattice. The resulting artificial structures successfully mimic the geometric and topological features of real proteins, and therefore, provide the opportunity to understand characteristics of protein structures and lead to the creation of synthetic proteins. The proposed method does not involve a chain-fitting step and does not require individual set of reference structures. We start with a cubic lattice, whose lattice sites contain beads representing protein residues. Many cubic lattices are emptied up to 60% vacancy concentration by randomly removing beads while maintaining a connected network of occupied sites. The maximum vacancy concentration of 60% was obtained from first and second nearest neighbor occupancies of real protein residues. A Reverse Monte-Carlo/Simulated Annealing (RMC/SA) simulation that is constrained to fit the average radial distribution function of residues of 278 proteins is then performed. Results indicate that the RMC/SA procedure recovers the average radial distribution function without disturbing other structural properties such as bond orientational order parameters and network topology. Based on various structural properties, our results indicate that these artificially created structures closely resemble real residue networks.

Formation of compounds and Kirkendall vacancy in the Cu–Sn system

The Cu/Sn system is one of the simplest metallurgical options for three-dimensional (3D) microbumps. Even at room temperature, however, intermetallic compounds of Cu3Sn and Cu6Sn5 are formed at the interconnection between Cu and Sn, and voids are produced inside the microbump. The formation of compounds and voids deteriorates mechanical and electrical properties of the microbump and thus causes potential reliability issues. Among various root causes of voids in microbumps, the void formation due to Kirkendall effect was examined in the present study. The Kirkendall effect provides the lower limit of the void formation in the Cu/Sn microbump. In order to develop a criterion for the maximum vacancy concentration in the Cu/Sn system, the growth of intermetallic compounds and the formation of Kirkendall vacancy in the binary C–Sn system were studied by simulation using an analytical diffusion model and experimental results under an assumption of atomic exchange mechanism for diffusion. The fraction of Kirkendall vacancy was calculated and then plotted against the distance representing the Cu/Cu3Sn, Cu3Sn/Cu6Sn5 and Cu6Sn5/Sn interfaces in semi-infinite diffusion couples. Among these three interfaces, a maximum vacancy fraction of about 0.0125 was realised at the location close to the initial Cu/Cu3Sn interface at an annealing temperature of T=473K for an annealing time of t=1h. The penetration depth of vacancy is much greater on the Cu3Sn side than on the Cu side. This implies that Kirkendall voids may be predominantly formed on the Cu3Sn side of the Cu/Cu3Sn interface. To confirm validity of the simulation, the growth behaviour of intermetallic compounds and the formation of Kirkendall voids were experimentally observed using Cu/Sn diffusion couples prepared by an electroplating technique. The fraction of Kirkendall void in the diffusion couple annealed at T=473K for t=1h was measured by binary large objects (Blob) analysis. According to the observation, a row of Kirkendall voids is formed in Cu3Sn along the direction parallel to the Cu/Cu3Sn interface, where the measured value of void fraction is 0.0112. If most of Kirkendall vacancies are used to form Kirkendall voids, the void fraction is almost equal to the vacancy fraction. Thus, the simulation satisfactorily reproduces the experiment. The growth behaviour of the intermetallic compounds in the present Cu/Sn diffusion couple well coincides with that observed for a semi-infinite Cu/Sn diffusion couples in a previous study.

Analysis of Stress Induced Voiding Using by Finite Element Analysis Coupled with Finite Difference Analysis

In this paper, the vacancy migration in Cu interconnect of large scale integration caused by stress induced voiding was calculated using the α multiplication method. Then, the effect of weight coefficient, α, on stress induced vacancy diffusion analysis was investigated and the validity of the α multiplication method was verified. Furthermore, the method of the vacancy diffusion analysis coupled with thermal stress analysis which can consider the history of thermal stress due to temperature changes was proposed. The results of the vacancy diffusion analysis coupled with the thermal stress analysis were compared with the analytical results of the vacancy migration without the effect of history of thermal stress. As a result, the maximum site of vacancy accumulation was found to be qualitatively in good agreement between them. However, the quantitative value of maximum vacancy concentration obtained by the vacancy diffusion analysis coupled with thermal stress analysis was found to be much higher and the vacancy distribution is found to be much more localized.

Molecular dynamics simulation of porous layer-induced stress in Fe single crystal

Pipeline steel in soil containing water could induce a macro tensile stress, leading to stress corrosion cracking (SCC). Porous layer-induced stress in Fe single crystal with various vacancy distributions on the surface layer is studied using molecular dynamics. The results show that Fe single crystal with one end fixed and a porous layer on the surface is deflected toward the porous layer during relaxation, resulting in a macro tensile stress. There is a maximum tensile stress in the matrix near the interface between the porous layer and the matrix resulting from the porous layer. The average stress on the porous layer σ xx ( d), which is calculated based on the measured deflection, increases with the increase of the maximum vacancy concentration C V on the top surface and the relative depth of the porous layer d/ B. And the macro tensile stress σ xx ( B) on the cross section of the sample increases also with the increase of C V and d/ B. σ xx ( B) is approximately four times smaller than σ xx ( d).

Synthesis, characterization, and electrical conductivity of new Aurivillius-type oxide-ion conductor

A new oxide-ion conductor of Aurivillius family with a general formula Bi2AlxV1 − xO5.5 − x − δ; 0 ≤ x ≤ 0.20 (BIALVOX) was synthesized by the sol-gel citrate route. Powder X-ray diffraction and simultaneous thermogravimetric and differential thermal analyses confirmed that the calcination of BIALVOX xerogels is fully completed at around 500°C after three hours of thermal treatment. It has been found that the β-orthorhombic phase is stabilized with compositions x ≤ 0.07, whereas the stabilization of the γ′-phase takes place for x ≥ 0.10. AC impedance spectroscopic investigation suggested that the charge accumulation at grain boundaries is thermally activated process. However, the maximum electrical conductivity (7.73 × 10−5 S cm−1) noticed for BIALVOX.13 at 300°C was attributed to the maximum vacancy concentration in the equatorial planes, responsible for the ion diffusion through the structure. This has been further evidenced by the temperature dependence of dielectric permittivity.

Oriented nanometer surface morphologies by thermal relaxation of locally cross-linked and stretched polymer samples

We present a technique to fabricate polymer substrates with locally structured surfaces in the nanometer scale. By ion projection direct cross-linking the surface of a stretched polymer is locally cross-linked and afterwards annealed above the glass transition temperature to induce surface rippling. The rippling periodicity depends on the thickness of the cross-linked surface layer, formed through hydrogen vacancies, which are generated by the ion bombardment. We systematically studied the effect of the projectile mass on the hydrogen vacancy distribution in polystyrene (PS) samples. Simulations revealed a decreasing depth of the maximum hydrogen vacancy numbers by increasing projectile mass. This value can be correlated to the thickness of the cross-linked PS layer, which directly determines the ripple periodicity. An additional Au capping layer was used to further reduce the cross-linked layer thickness to a few nanometers. By this, defined structures with a ripple periodicity of 250 nm were fabricated. In addition, the technique allows inferring the Young’s modulus of thin cross-linked PS layers.