Inert Gas Condensation Research Articles

Tailoring magnetic exchange coupling in Zr2Co11/FeCo nanocomposites via dual-source inert gas condensation: a one-step synthesis approach

Abstract This study investigated the synthesis and magnetic properties of Zr2Co11/FeCo nanocomposites via a one-step dual-source inert gas condensation method. The composite particles were prepared with varying FeCo mass percentages (5%, 10%, and 15%), and their structural and magnetic characteristics were examined. X-ray diffraction confirmed the successful integration of FeCo into the Zr2Co11 matrix. Magnetic measurements revealed enhanced saturation magnetization and effective exchange coupling in Zr2Co11/FeCo-1 and Zr2Co11/FeCo-2. However, excessive FeCo in Zr2Co11/FeCo-3 resulted in less efficient coupling, as indicated by kinks in the hysteresis loop and negative regions in the Henkel plot. These findings underscore the importance of optimizing FeCo content to achieve superior magnetic properties, offering potential for advanced magnetic materials.

Reliable Atom Probe Tomography of Cu Nanoparticles Through Tailored Encapsulation by an Electrodeposited Film.

Nanoparticles are essential for energy storage, catalysis, and medical applications, emphasizing their accurate chemical characterization. However, atom probe tomography (APT) of nanoparticles sandwiched at the interface between an encapsulating film and a substrate poses difficulties. Poor adhesion at the film-substrate interface can cause specimen fracture during APT, while impurities may introduce additional peaks in the mass spectra. We demonstrate preparing APT specimens with strong adhesion between nanoparticles and film/substrate matrices for successful analysis. Copper nanoparticles were encapsulated at the interface between nickel film and cobalt substrate using electrodeposition. Cobalt and nickel were chosen to match their evaporation fields with copper, minimizing peak overlaps and aiding nanoparticle localization. Copper nanoparticles were deposited via magnetron sputter inert gas condensation with varying deposition times to yield suitable surface coverages, followed by encapsulation with the nickel film. In-plane and cross-plane APT specimens were prepared by femtosecond laser ablation and focused ion beam milling. Longer deposition times resulted in agglomerated nanoparticles as well as pores and voids, causing poor adhesion and specimen failure. In contrast, shorter deposition times provided sufficient surface coverage, ensuring strong adhesion and reducing void formation. This study emphasizes controlled surface coverage for reliable APT analysis, offering insights into nanoparticle chemistry.

Physical, optical properties and antibacterial activity of silver nanoparticles: Nanoclusters to nanoparticles formation on glass substrate by in-situ annealing

Silver nanoparticles (AgNPs) formed on in-situ annealed microscopic glass substrates from silver nanoclusters (AgNCs) generated by DC magnetron sputtering with inert gas condensation (IGC) technique. The substrate’s annealing temperature was below and above the glass transition temperature of 500 ºC and 600 ºC. The influence of annealing temperature on the surface morphology was studied using atomic force microscopy (AFM). X-ray photoelectron spectroscopy (XPS) and ultraviolet photoelectron spectroscopy (UPS) were employed to investigate the surface composition, chemical states, and electronic states of the AgNPs on the glass substrates. On the in-situ annealed glass substrate at 500 ºC, the produced AgNPs revealed accumulation and aggregation. For in-situ annealed at 600 ºC, a homogeneous distribution of AgNPs on the glass substrate was witnessed. The refractive index test revealed that AgNPs deposition at 600 ºC achieved higher sensitivity with 27 nm/RIU (Refractive index unit). The antibacterial activity of AgNPs was also investigated using Escherichia coli and Bacillus cereus. In contrast, better antibacterial activity was obtained with in-situ annealing at 500 ºC, where 4-fold reductions compared with the control sample. Pre-determined properties can be precisely executed to achieve the desired performance as the so-called application-oriented engineered surface in the UHV system is established. This research highlighted the differences between two different annealing temperatures' effect on the base substrate material, which subsequently impacts the structure of AgNPs and their applications. Furthermore, the outcome of this work could contribute to the multifunctional surface for detecting heavy metals, various organic pollutants, and disinfection of water and food-borne pathogenic diseases.

Atomic Structure Amorphization and Electronic Structure Reconstruction of FeCoNiCrMox High-Entropy Alloy Nanoparticles for Highly Efficient Water Oxidation.

The complexity of the multielement interaction in high-entropy alloys (HEAs) may provide more active sites to adapt different catalytic reaction steps in oxygen evolution reaction (OER). Investigating the correlation between structure and performance of HEAs electrocatalysts is both essential and challenging. In this work, FeCoNiCrMox HEAnanoparticles are successfully fabricated utilizing a unique nanofabrication method called inert gas condensation. With the increase of high-valence metal component Mo, the atomic structure amorphization and electronic structure reconstruction are unveiled. According to the X-ray photoelectron spectroscopy valence spectra, the d-band center of FeCoNiCrMox is ascending, and thus enhancing the adsorption energy. Synchrotron pair distribution function analysis reflects the degree of structural disorder and reveals a robust correlation with the intrinsic OER activities of the electrocatalysts. FeCoNiCrMo1.0 high-entropy metallic glass nanoparticles exhibit an outstanding OER performance with an ultralow overpotential of 294.5mV at a high current density of 100mAcm-2. This work brings fundamental and practical insights into the modulation mechanism of metal components of HEAs catalysts for developing OER.

Recent progress and future directions in nanoglass materials: A deep insight into synthesis, characterization, and application

This review article provides a comprehensive examination of the most recent advances in research on nanoglasses, including the methods used to create these materials, their characteristics, and their diverse range of uses. An overview of the current trends in nanoglass research connects them to the Sustainable Development Goals, highlighting the current relevance of this topic. The process of manufacturing nanoglasses is explained in depth, highlighting advanced approaches such as inert gas condensation and severe plastic deformation, among other techniques. The prime focus of this review is on analyzing the various dimensions of nanoglass materials, including their structural dynamics and electrical configurations, and how these features contribute to their exceptional thermal stability and mechanical strength. The magnetic characteristics of nanoglasses are examined, highlighting their potential for driving innovation across multiple industries. The primary emphasis is on the biological usefulness of nanoglasses, specifically examining their bioactivity and interaction with biological components, and emphasizing their growing use in nanoscale biomedical applications. With regard to the practical applications of nanoglasses, there are specific discussions of their contributions to biological evaluation, wound healing, catalysis, and environmental sustainability. There is an emphasis on the durability and resistance of nanoglasses in these contexts. The comprehensive overview of nanoglasses provided in this article highlights their significance as revolutionary materials in fields of science and technology. The potential of nanoglasses to contribute to a future that is more sustainable and health oriented is indicated. The article ends by discussing the future directions for nanoglass research and looks forward to the promising possibilities for further investigation and innovation.

Enhancement of copper nanoparticle yield in magnetron sputter inert gas condensation by applying substrate bias voltage and its influence on thin film morphology

Large-scale synthesis of high-purity nanoparticles is an intense topic of scientific research, with magnetron sputter inert gas condensation recognized as a promising, environmentally friendly technique avoiding wet chemical processes. This study explores the deposition of size-selected nanoparticles under varied substrate bias voltages and reports on a consequent increase in deposition rates up to 32 %. These alterations in substrate bias voltage induce a progressive change in the morphology of the resulting nanoparticle thin films, attributable to the increased kinetic energy of the nanoparticles. Comprehensive characterization via quadrupole mass spectroscopy of the nanoparticle flux, scanning electron microscopy, X-ray photoelectron spectroscopy, and low-energy ion scattering spectroscopy of the deposited nanoparticles corroborates the enhanced nanoparticle yield associated with increased substrate bias voltage. These findings signify a methodological advancement, enhancing the efficiency of magnetron sputter inert gas condensation and moving the technology a step further towards feasible industrial production.

Effect of external electric and magnetic fields on the structural properties of gold nanoclusters formed during inert-gas condensation process in different environments using molecular dynamics simulations

In this article, we have investigated growth path, stabilities, and structures of formed Au nanoclusters during the gas phase process with different environments (water and Ar) in the presence of external electric and magnetic fields using molecular dynamics (MD) simulation. Our results showed that the number of the formed cluster increases by applying the strong magnetization. By increasing the concentration of water in 50% H2O–50% Ar and in 100% H2O environments and applying a magnetic field, the hollow porous (HP) nanoparticles are created, which can be considered as a new method for the formation of HP nanoparticles. Applying the stronger magnetic field increase the rate of formation of HP nanoparticles at larger simulation times. The number of HP nanoparticles also increases in the presence of strong and weak electric fields by increasing the concentration of water in the environment.

Enhanced solid solubility in hcp Co(Mo) nanoparticles formed via inert gas condensation

Co–Mo alloy clusters with extended solubility of Mo in hcp Co were produced by inert gas condensation (IGC). While the equilibrium solubility of Mo in hexagonal close-packed (hcp) Co is on the order of 1 atomic percent, the non-equilibrium aspects of IGC resulted in ~ 18 atomic percent Mo dissolved in hcp Co. The extended solid solutions and hcp structure were observed across all of the processing conditions, which included variation of sputtering power and aperture size. There was, however, variation of nanoparticle size and magnetic behavior with processing parameters. The Co(Mo) nanoparticles were ferromagnetic at room temperature. Coercivities of the nanoparticles produced with a 2.5-mm aperture were independent of sputtering power and significantly higher than those of the nanoparticles produced with a 7-mm aperture. The coercivities of the nanoparticles produced with a 7-mm aperture were slightly power-dependent. Overall, there appeared to be a relationship between coercivity and nanoparticle size.

Physical methods for preparation of nanomaterials, their characterization and applications: a review

AbstractNanotechnology refers to nanomaterials of different dimensions, ranging in size from 1 to 100 nm. Shape and size, as well as properties of nanomaterials, depend on the materials based on their production. Nanomaterials are classified according to the type of substrate into carbon-based nanomaterials, metal-based nanomaterials, ceramic nanomaterials, lipid-based nanomaterials, semiconductor nanomaterials, and polymer nanomaterials. There are many physical methods that are widely used to produce nanomaterials, among these methods are inert gas condensation (IGC), physical evaporation, electric arc discharge, sputtering, and laser methods. Many characterization analysis techniques of nanomaterials, including ultraviolet–visible (UV–V) spectroscopy, XRD (X-ray diffraction), BET (Brunauere emmette teller), FESEM (Field emission scanning electron microscopy), FTIRS (Fourier transform infrared spectroscopy), TEM (Transmission electron microscopy) and Zeta size analysis. The unique properties that distinguish nanomaterials, allows them to penetrate many applications that directly serve the world. Nanomaterials have been utilized in various applications in the environment, agriculture, food industries, medical industries, chemical processing, and military industries.

Exploring the nanoscale: AFM-IR visualization of cysteine adsorption on gold nanoparticles

This study focuses on the adsorption process of L-cysteine (Cys), a sulfur-containing amino acid, onto monolayers of gold nanoparticles (AuNPs) prepared through distinct protocols on mica substrates. Two types of AuNPs were prepared using two different methods: the first employed a physical approach, which combined the Inert Gas Condensation (IGC) technique with the magnetron sputtering method, while the second utilized a chemical method involving the reduction of tetrachloroauric acid with trisodium citrate (TC). The characterization of AuNPs was performed using transmission electron microscopy (TEM) and atomic force microscopy (AFM), of up to 5 ± 1.3 nm for bare AuNPs obtained through vacuum techniques, and up to 12 ± 5 nm for negatively charged, citrate-stabilized TCAuNPs(−). The application of spectroscopic techniques based on the surface-enhanced effects allows for describing the adsorption process in both micro- and nanoscale systems: Cys/bare AuNPs and Cys/ TCAuNPs(−). The commonly used surface-enhanced Raman spectroscopy (SERS) technique provided insights into adsorption behaviours at the microscale level. In the case of TCAuNPs(−), an interaction involving the lone electron pair of sulfur (S) atom and metal surface, while on the bare AuNPs, S is adsorbed on the surface, but the cleavage of the SH group is not discernible. Nanoscale analysis was complemented using AFM combined with the surface-enhanced infrared absorption spectroscopy (AFM-SEIRA) technique. AFM-SEIRA map indicated the formation of hot spot which were predominantly located between aggregated TCAuNPs(−) and on specific NPs surfaces (area between NPs and gold-coated tip). Results from the SERS and AFM-SEIRA techniques were in good agreement, underscoring the comprehensive understanding achieved through the chosen experimental approach regarding the Cys interactions with layers of AuNPs.

Effect of water and ionic liquid vapors on the structural properties of gold nanoclusters formed during inert-gas condensation process using molecular dynamics simulations

In this research, process of Au nanocluster formation has been investigated using the inert-gas condensation process in different environments with different concentrations of Ar gas, water vapor, and IL molecules. We have calculated the total energy, relative stability, surface energy, and radial distribution function (RDF) of the different produced clusters at different simulation times. Our results showed that the number of formed clusters increases, whereas their size decreases by increasing the water and IL concentrations in the environment. The water and IL molecules adsorb on the nanoclusters surfaces and hinder the coalescence of the smaller clusters to form bigger clusters. The percentage of the fcc and hcp atoms also decreases by increasing the water and IL concentrations. The produced clusters also become more non-spherical by increasing the IL and water vapor in the environment (with exception of the pure vapors).

Unveiling the correlation between anomalous hardening and grain boundary diffusional transformation in ω single-phase nano-grained Ti-Fe alloy

A metastable ω single-phase nanograined (NG) Ti-Fe alloy was synthesized using laser inert-gas condensation (IGC). Upon being annealed at 360 °C, the NG Ti-Fe alloy exhibited a remarkable ultra-hardening, increasing the hardness from 4.7 to 8.6 GPa. Subsequent findings revealed an unexpected hardness enhancement, rising from 6.6 GPa at 420 °C to 7.6 GPa at 460 °C, despite the occurrence of grain growth. In-depth investigations into the strengthening mechanisms of the NG Ti-Fe alloy were conducted using in-situ synchrotron high-energy X-ray diffraction (XRD) and transmission electron microscopy (TEM). The comprehensive analysis unveiled that the diffusion-controlled structure evolution during annealing played a pivotal role in enhancing the alloy’s mechanical properties. This study not only presents the synthesis of a novel metastable alloy but also provides valuable insights into the intricate relationship between diffusion-controlled structure evolution and the resulting superior mechanical properties.

Vibration Sensors on Flexible Substrates Based on Nanoparticle Films Grown by Physical Vapor Deposition.

Flexible electronics have gained a lot of attention in recent years due to their compatibility with soft robotics, artificial arms, and many other applications. Meanwhile, the detection of acoustic frequencies is a very useful tool for applications ranging from voice recognition to machine condition monitoring. In this work, the dynamic response of Pt nanoparticles (Pt NPs)-based strain sensors on flexible substrates is investigated. the nanoparticles were grown in a vacuum by magnetron-sputtering inert-gas condensation. Nanoparticle sensors made on cracked alumina deposited by atomic layer deposition on the flexible substrate and reference nanoparticle sensors, without the alumina layer, were first characterized by their response to strain. The sensors were then characterized by their dynamic response to acoustic frequency vibrations between 20 Hz and 6250 Hz. The results show that alumina sensors outperformed the reference sensors in terms of voltage amplitude. Sensors on the alumina layer could accurately detect frequencies up to 6250 Hz, compared with the reference sensors, which were sensitive to frequencies up to 4250 Hz, while they could distinguish between two neighboring frequencies with a difference of no more than 2 Hz.

Molecular dynamics investigation of gold nanoparticle coalescence under realistic gas-phase synthesis conditions

Dependence of nanoparticle (NP) coalescence on various physical parameters (e.g., temperature, number of NPs, NP size, orientation, crystallinity, shape, or composition, etc.) is a very active field of investigation. However, most computational studies on NP coalescence to date are performed in vacuum, with only a handful of studies taking gas pressure into account and even fewer doing a systematic analysis. This is due to two reasons: first, many computational studies complement inert-gas condensation experiments, which typically happen at high vacuum. Second, a simulation set-up in vacuum is simpler and computationally less costly. Here we utilised classical molecular dynamics for a rigorous investigation of the effect (or lack of) of gas pressure, as well as of other parameters (namely temperature, angular momenta, and inert-gas species), on the early stages of coalescence between two metallic NPs. Our approach is relevant for both inert-gas condensation in high vacuum and aerosol synthesis in standard atmospheric conditions. Multiple linear regression analysis confirmed temperature as the key factor determining the degree of coalescence; relative angular momenta direction was revealed as yet another important contributor, whereas the effect of pressure was deemed insignificant for early coalescence stages. To shed light onto the sintering process we elaborate on interesting atomistic mechanisms. We aspire that our study may indicate potential strategies for both gas-phase synthesis methods.

In situ and ex situ quantification of nanoparticle fluxes in magnetron sputter inert gas condensation: A Cu nanoparticle case study

Magnetron sputter inert gas condensation was coupled with quadrupole mass spectrometry for the in situ characterization of a nanoparticle beam. The proposed method allows us to determine the size distribution and the mass flux of the nanoparticles. The measured quadrupole mass spectrometer grid current is converted into a nanoparticle flux and subsequently into a mass flux. Cu nanoparticles were deposited onto Si substrates using different filtering modes of the quadrupole mass spectrometer. Characterization was carried out using a combination of x-ray photoelectron spectroscopy and scanning electron microscopy. Quantitative analysis of the elemental composition of the Si surface revealed a Gaussian distribution of the deposited nanoparticles over the diameter of the rotating substrate holder with a good quantitative agreement with the predictions made from the in situ quantification method.

Synthesis of silver-palladium Janus nanoparticles using co-sputtering of independent sources: experimental and theorical study.

Janus-type nanoparticles are important because of their ability to combine distinct properties and functionalities in a single particle, making them extremely versatile and valuable in various scientific, technological, and industrial applications. In this work, bimetallic silver-palladium Janus nanoparticles were obtained for the first time using the inert gas condensation technique. In order to achieve this, an original synthesis equipment built by Mantis Ltd. was modified by the inclusion of an additional magnetron in a second chamber, which allowed us to use two monometallic targets to sputter the two metals independently. With this arrangement, we could find appropriate settings at room temperature to promote the synthesis of bimetallic Janus nanoparticles. The structural properties of the resulting nanoparticles were investigated by transmission electron microscopy (TEM), and the chemical composition was analyzed by TEM energy dispersive spectroscopy (TEM-EDS), which, together with structural analysis, confirmed the presence of Janus-type nanostructures. Results of molecular dynamics and TEM simulations show that the differences between the crystalline structures of the Pd and Ag regions observed in the TEM micrographs can be explained by small mismatches in the orientations of the two regions of the particle. A density functional theory structural aims to understand the atomic arrangement at the interface of the Janus particle.

N‐Doping Effects On Electrocatalytic Water Splitting of Non‐Noble High‐Entropy Alloy Nanoparticles Prepared by Inert Gas Condensation

AbstractThe unique catalytic activities of high‐entropy alloys (HEAs) emerge from the complex interaction among different elements in a single‐phase solid solution. As a “green” nanofabrication technique, inert gas condensation (IGC) combined with laser source opens up a highly efficient avenue to develop HEA nanoparticles (NPs) for catalysis and energy storage. In this work, the novel N‐doped non‐noble HEA NPs are designed and successfully prepared by IGC. The N‐doping effects of HEA NPs on oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) are systematically investigated. The results show that N‐doping is conducive to improving the OER, but unfavorable for HER activity. The FeCoNiCrN NPs achieve an overpotential of 269.7 mV for OER at a current density of 10 mA cm−2 in 1.0 M KOH solution, which is among the best reported values for non‐noble HEA catalysts. The effects of the differences in electronegativity, ionization energy and electron affinity energy among mixed elements in N‐doped HEAs are discussed as inducing electron transfer efficiency. Combined with X‐ray photoelectron spectroscopy and the extended X‐ray absorption fine structure analysis, an element‐design strategy in N‐doped HEAs electrocatalysts is proposed to improve the intrinsic activity and ameliorate water splitting performance.

Ag Nanocluster Production through DC Magnetron Sputtering and Inert Gas Condensation: A Study of Structural, Kelvin Probe Force Microscopy, and Optical Properties.

Silver nanoclusters are valuable for a variety of applications. A combination of direct current (DC) magnetron sputtering and inert gas condensation methods, employed within an ultra-high vacuum (UHV) system, was used to generate Ag nanoclusters with an average size of 4 nm. Various analytical techniques, including Scanning Probe Microscopy (SPM), X-ray Diffraction (XRD), Kelvin Probe Force Microscopy (KPFM), UV-visible absorption, and Photoluminescence, were employed to characterize the produced Ag nanoclusters. AFM topographic imaging revealed spherical nanoparticles with sizes ranging from 3 to 6 nm, corroborating data from a quadrupole mass filter (QMF). The XRD analysis verified the simple cubic structure of the Ag nanoclusters. The surface potential was assessed using KPFM, from which the work function was calculated with a reference highly ordered pyrolytic graphite (HOPG). The UV-visible absorption spectra displayed peaks within the 350-750 nm wavelength range, with a strong absorption feature at 475 nm. Additionally, lower excitation wavelengths resulted in a sharp peak emission at 370 nm, which became weaker and broader when higher excitation wavelengths were used.

Characterization on microstructure evolution of a bulk nanograined TiZrHfNb refractory high-entropy alloy

A bulk TiZrHfNb nanograined refractory high-entropy alloy (NG-RHEA) with an average grain size of 31.6 nm was prepared by inert gas condensation (IGC) method. In the initial as-IGC sample, it is composed of a body-centered cubic structure and an amorphous phase accounting for about 25%. Then the microstructure was regulated by annealing at 200 °C, 400 °C and 600 °C for 0.5 h. The results show that a dual-phase structure composed of body-centered cubic phase nanograins and amorphous phase was maintained below 400 °C. Significant grain growth was observed when annealed at 600 °C, with obvious phase decomposition detected. The hardness of as-IGC TiZrHfNb NG-RHEA increases from 348 HV to 432 HV after annealed at 400 °C. The relationship between microstructure and hardness was discussed. This work provides insights into the preparation and structure modulation of bulk NG-RHEAs.

Enhanced activity and durability of FeCoCrMoCBY nanoglass in acidic hydrogen evolution reaction

In the present work, a multi-element nanoglass (m-NG) of FeCoCrMoCBY is obtained first time by the laser ablation combined with inert gas condensation (laser-IGC) technique. Compared with the conventional rapid-quenched metallic glass (MG) with identical composition, the Fe-based m-NG demonstrates a superior performance as a self-supported electrocatalyst for hydrogen evolution reaction (HER) in acidic solution. The enhanced HER activity of m-NG is proposed to be closely related to its high energy states, which is originated from the unique inhomogeneous nanostructures with a high density of low-coordinated atoms. Additionally, the Fe-based m-NG exhibits an outstanding comprehensive catalytic performance even beyond the commercial Pt/C catalyst in long-term test due to its self-optimization ability. This work not only opens the way to the preparation of m-NGs by the novel laser-IGC technique, but also makes a great contribution to developing low-cost, high-efficient, and super-durable HER electrocatalysts in acidic environment.