Argon Beam Research Articles

Subsurface Characteristics of Metal-Halide Perovskites Polished by an Argon Ion Beam

Subsurface Characteristics of Metal-Halide Perovskites Polished by an Argon Ion Beam

Pore Distribution Characteristics of Different Lithofacies Shales: Evidence from Scanning Electron Microscopy

To disclose the pore distribution characteristics of different lithofacies lacustrine shales, ten samples collected from the Shahejie Formation, Dongying Sag, Bohai Bay Basin, China, were examined using argon ion beam milling–scanning electron microscopy (SEM). A quantitative method was adopted to characterize shale pore distributions based on the SEM images. Mercury intrusion capillary pressure was employed to determine the pore throat size distributions of the shales. The SEM images indicated that in shale reservoirs, interparticle pores at the edges of brittle particles and intraparticle pores in clay mineral aggregates primarily contribute to the reservoir spaces and that in calcite-rich shales, dissolution pores provide secondary reservoir space. Among the morphologies of dissolution, intraparticle, and interparticle pores, the morphology of the dissolution pores is the simplest, followed by those of intraparticle and interparticle pores in that order. Clay and felsic minerals primarily control the shale pore sizes and the larger the clay mineral content in the shales, the smaller their pore size; the felsic minerals demonstrate the opposite behavior. The image-based point counting data indicate that shale pore sizes are mostly between 20 nm and 2 μm. In contrast, most pore throats are less than 20 nm in diameter, implying that the pores in the nanometer to micrometer scales are connected by tiny throats. Among the four lithofacies shales, felsic-rich shales are favorable for shale oil accumulation and seepage because of their large pore sizes and throats their ability to form intercalated shale oil adjacent to organic-rich shales. Calcareous shales with a large number of dissolution pores and a large content of organic matter could produce self-generation and self-storage matrix shale oil and would typically develop fractures, thereby creating a seepage channel for shale oil. This study presents the micro-distributions of different lithofacies of shale pores, which would help in understanding the occurrence and seepage of oil in shale reservoirs.

Tuning the oxidation state of titanium dioxide mesoporous film by 1000 eV argon ion beam irradiation

This work proposes the creation of oxygen vacancies on the surface of TiO2 mesoporous film using a 1000 eV argon ion (Ar+) beam. After X-ray photoelectron spectroscopic characterization, the survey spectra of TiO2 nano-particles reveal the presence of oxygen (with chemical state O 1s), titanium (with chemical state Ti 2p), carbon (with chemical state C 1s) and argon (with chemical state Ar 2p) while the concentrations of each chemical states vary with an irradiation time of the Ar+ beam. The acquired Ti 2p spectra show five peaks at high resolution which correspond to Ti4+ 2p3/2, Ti4+ 2p1/2, Ti3+ 2p3/2, Ti3+ 2p1/2, and Ti2+ 2p1/2. The concentrations of Ti2+ and Ti3+ increase with irradiation time while the concentrations of Ti4+ decrease as the irradiation time increases. Three peaks characterize high-resolution spectra of O 1s which correspond to lattice oxygen, oxygen vacancy, and adsorbed oxygen. The peak area of lattice oxygen decreases with irradiation time while that of oxygen vacancies increases with irradiation time which shows the creation of oxygen vacancies at the expense of contaminant removal due to Ar+ exposure. Valence spectra analysis shows an insignificant effect on the valance band as the sample exposure to Ar+ increases. This proposed method of oxygen vacancy creation would facilitate the effective utilization of TiO2-based semiconductors in addressing many photo-catalytic challenges and widening the sunlight absorption capacity of the semiconductor.

Ion source and low energy beam transport prototyping for a single-ended heavy ion ToF-ERDA facility

We present the status of the ion source and low energy beam transport prototyping activities for a heavy ion time-of-flight elastic recoil detection analysis (ToF-ERDA) equipment, designed to accelerate a flux of 1–10 particle nano-Ampere of 40Ar6-12+ ions to 3–6MeV energy for depth profiling of light elements. The prototype injector consists of a novel permanent magnet electron cyclotron resonance ion source CUBE-ECRIS with a minimum-B quadrupole field topology, and a 90° permanent magnet dipole with adjustable field strength for charge state selection. We report experimentally measured argon beam currents as a function of the applied microwave power and ion source potential to demonstrate the feasibility of the CUBE-ECRIS as an injector for a single-ended ToF-ERDA facility with the ion source and low energy beam transport on a 500kV platform without SF6 electrical insulation. Finally, we present the design and field measurement results of the dipole magnet prototype.

Regression Dependences of Mechanical Properties of Aluminum Alloys Exposed to Accelerated Argon Ion Beams

Regression Dependences of Mechanical Properties of Aluminum Alloys Exposed to Accelerated Argon Ion Beams

Study of the characteristics of the system: Ion source-ion decelerator.

The features of the method for the formation of dense low-energy ion beams in the system consisting of ion source-ion decelerator are considered. According to this method, a wide ion beam is formed using an ion source with an ion energy of 500eV and higher, and then the ions are decelerated just before landing on the substrate surface by an electric field created in the ion decelerator. In the considered ion decelerator, the electric field that slows down the ions is created in a gas discharge in E × B fields due to the Hall effect. The decelerated electrode imitating the substrate is located in the field of action of a magnetic field with an induction of 0.45T. The ion decelerator is characterized as a Hall magnetohydrodynamic converter of the ion beam kinetic energy into electrical energy. The analysis of plasma processes in the converter has been carried out on the basis of the model of the ion-vacuum regime of a discharge in E × B fields for estimating the expected properties of the converter and their verification based on experimental results. In experiments, an ion source of the Kaufman type formed an argon ion beam with a density of 0.5-2 mA/cm2 and ion energy of 300-1500eV was used. The voltage-current characteristics of the converter are given. The ratio of electron and ion components of the current in the circuit of the decelerated electrode was determined when the beam space charge neutralizer in the form of a heated filament was switched on and off. Using a Langmuir probe and a thermionic probe, the distributions of the ion beam current density and the potential of the plasma surrounding the ion beam in the beam transport space has been studied. A significant influence of the potential of the decelerator electrode on the plasma potential in the region of ion beam transport is shown. The features of the discharge in a specific design of the ion decelerator for a deceleration degree of ions to an energy of 50-75eV are revealed.

Amined polyallylamine particles synthesized by plasma

AbstractThis work presents the synthesis of polyallylamine (PAl) particles starting from allylamine using resistive‐inductive electrical glow discharges. PAl particles obtained directly from allylamine had not been reported before, only in combination with other components. PAl has a great number of applications as a biomaterial, due among other things to its great amine content. The particles were synthesized with a spherical profile with diameter in the 47–2900 nm range and were eroded with an Argon beam in a X‐ray photoelectron spectrometer to calculate the amine content inside. Primary (4%–10%), secondary (38%–49%), tertiary (7%–31%), and unsaturated (22%–41%) amines were found in the particles as a function of the power of synthesis. Analyzing from the surface to the interior of the particles, the results showed that secondary amines slightly reduce, and tertiary amines increase. The electric conductivity of the particles was calculated as a function of temperature in the 10−8–10−4 S/m interval with a semiconductor behavior increasing as the diameter reduces. The electrical properties are important in the application of these particles in the central nervous system.

Overview of technical solutions for improving of magnetron sputtering devices

The paper provides a brief overview of technical solutions that allow expanding the capabilities of magnetron sputtering systems using different options for organizing an external source of charges. Among them, the following are considered in detail: electron emission in the magnetron discharge track; argon ionization in the space above the target; argon ionization in the vacuum chamber volume; the use of an uncooled "hot" target; bombardment of the target surface with a beam of argon ions. Among the solutions considered, a combination of a magnetron with an ion source or an incandescent cathode is noted, which in principle can provide equal-dimensional reactive sputtering on "long" (more than 1 m) magnetrons and flexible control of the properties of coatings intended for dimensional elements of equipment of the fuel and energy and oil and gas complexes, as well as solutions based on spraying a "hot" target, which can find industrial application for the formation of thermal barrier coatings on the blades of modern power gas turbines and aviation gas turbine engines.

SJLA_2024_A18: Persistent Complex Seroma Treated by Capsulectomy and Argon Beam Coagulator

Background: Seroma formation is one of the most common events following ventral hernia repair. When mesh is used for the repair of larger and more complex incisional hernias, the risk of seroma formation increases. The mesh onlay technique, which requires more extensive dissection, is associated with an even greater incidence of seroma formation. Treatment options for postoperative seromas include observation for spontaneous resolution, percutaneous aspiration, closed suction drainage, abdominal binders, and sclerosant. Methods: The aim of this report is to present a definitive management of a very challenging case of abdominal wall chronic complex seroma following herniorrhaphy with mesh approached by open capsulectomy and scarification of the remnant pseudocapsule. Results: Our patient is a 60 years-old male a status post low anterior resection with covering loop ileostomy for rectal cancer. His diverting stoma was taken off after completing the adjuvant chemotherapy treatment. Seven months later, the patient has developed an enlarging midline incisional hernia. This hernia was subsequently repaired by primary fascial closure with suprafascial onlay polypropylene mesh. Postoperatively, he developed a subcutaneous seroma which was initially treated with an abdominal binder without success. Over the following 3 months of observation, seroma was increasing in size. Discussion: Having recovered his acute condition, surgical intervention was planned. The patient underwent an excision and evacuation of the complex seroma and pseudocapsule. A 12-cm midline incision was made in line with the previous incision used for the hernia repair. The pseudocapsule of the seroma was encountered when the subcutaneous tissue was incised. The incision was carried superior, inferior, and laterally, and the capsule was exposed. The seroma opening sinus was expanded and fluid was evacuated. There were some fibrous dead tissues and coagulated dark blood. The anterior and lateral aspects of the pseudo capsule were excised. Furthermore, the posterior aspect was cleaned carefully using the curettage instrument without affecting the integrity of the mesh which was looking healthy and intact and without causing injury to the intraabdominal contents. Argon beam coagulator was used to scarify the remaining posterior aspect attaching to the mesh. Hemostasis was secured, and the wound was closed over a Jackson–Pratt drain. A pressure dressing and abdominal binder were applied. Conclusion: Factors leading to seroma following incisional herniorrhaphy are poorly understood. Many options are available for treating complicated abdominal wall seroms. capsulectomy and scarification of the remnant pseudocapsule were good option for the treatment of persistence complex seroma.

Photodynamics of Bright Subnanosecond Emission from Pure Single-Photon Sources in Hexagonal Boron Nitride.

Bright and stable emitters of single indistinguishable photons are crucial for quantum technologies. The origin of the promising bright emitters recently observed in hexagonal boron nitride (hBN) still remains unclear. This study reports pure single-photon sources in multi-layered hBN at room temperature that demonstrate high emission rates. The quantum emitters are introduced with argon beam treatment and air annealing of mechanically exfoliated hBN flakes with thicknesses of 5-100 nm. Spectral and time-resolved measurements reveal the emitters have more than 1 GHz of excited-to-ground state transition rate. The observed photoswitching between dark and bright states indicates the strong sensitivity of the emitter to the electrostatic environment and the importance of the indirect excitation for the photodynamics.

Large area planar UV–Visible photodetectors using wide bandgap WO3−δ films

A simple synthesis technique of semiconducting monoclinic phase tungsten oxide (WO3−δ) films is demonstrated. In this article, we report the effect of oxidation temperature on oxygen vacancy gradient of WO3 films and their photo sensing properties. The WO3−δ films were grown on Si/SiO2 substrates by argon ion-beam sputtering of a high purity W (tungsten) target followed by thermal oxidization in the tubular furnace at three different oxidation temperatures at 500, 600 and 700 °C with controlled oxygen gas pressure. Detailed crystal structure, microscopic and spectroscopic characterizations reveal that the oxidation at temperature 700 °C produces reasonably good crystalline quality of the film exhibiting UV–Visible photo sensing properties. The effect of oxidation temperature towards an enhancement in crystallinity which in turn gives rise to sharp Raman peak is discussed. The fabricated device exhibits a very low dark current of 7.5 × 10 −8 A at ±0.5 V bias for WO3−δ films oxidized at 700 °C. The photodetection measurements show linear current-voltage (I–V) behaviour with light-to-dark current (ILight/IDark) ratio ∼102 at 365 nm illumination (∼0.82 mW cm−2) at 2 V applied bias. The responsivity (Rλ), specific detectivity (D*) and external quantum efficiency (EQE) were found to be ∼0.12 AW−1, ∼2.1 × 1010 Jones (cm Hz1/2 W−1) and 40%, respectively, at 365 nm illumination (∼0.82 mW cm−2) with an applied bias of 2 V for the films oxidized at 700 °C. While upon visible light illuminations, the Rλ, D* and EQE were calculated to be ∼0.78 AW−1, ∼1.4 × 1011 Jones and 174%, respectively, upon 555 nm illumination (∼0.21 mW cm−2), with 2 V applied bias. A faster photocurrent relaxation time was observed from the films oxidized at 700 °C. The ultraviolet photoelectron spectroscopy study shows a surface band gap of 3.7 eV with absolutely no density of states in the near Fermi-level, validating fully stoichiometric surface. The effects of oxidation temperatures causing the large bandgap are discussed in terms of the device performances.

Application of plasma technologies for increasing catalysts activity in the chemical industry

The article discusses the results of processing some catalysts used in the chemical industry using plasma technologies. The catalysts already used in production were treated in vacuum with a beam of argon ions with the addition of oxygen. The experiments were carried out with different values of the ion beam current and the energy of its ions. As a result of the experiments, it turned out that the characteristics of plasma-treated catalysts already used turned out to be close to those of fresh catalysts.

8811 Diaphragmatic Endometriosis: Anatomopathology and Correlation with Surgical Technique in 230 Patients Treated in a Referral Center

<h3>Study Objective</h3> To define a decision-making algorithm for Diaphragmatic Endometriosis (DE) surgical treatment correlating laparoscopic appearance of endometriotic implants with their histopatological counterpart. <h3>Design</h3> All the cases of DE surgically treated in Our Department, from January 2004 to January 2021, were analyzed in a retrospective chart review. <h3>Setting</h3> DE lesions were correlated to intraoperative findings (morphology, localization, side of the diaphragm, diameter, depth of infiltration and number) and classified according to their histopathological features as: •"Foci": bidimensional superficial peritoneal lesions, generally ≤ 1 cm diameter. •"Plaques": thin fibrotic lesions, thickening the diaphragmatic peritoneum with no muscular infiltration, > 1cm diameter. •"Nodules": solid, tridimensional implants, associated with partial or full-thickness infiltration of underneath muscle layers and generally > 1cm diameter. <h3>Patients or Participants</h3> Two hundred -thirty patients were collected. <h3>Interventions</h3> The histopathologic revision of all the specimens enabled us to select a different laparoscopic surgical approach, for each lesion, as the following: <h3>Measurements and Main Results</h3> •Argon Beam Coagulator (ABC) and/or Diathermocoagulation (DTC) for diaphragmatic foci; •Diaphragmatic stripping is indicated for endometriotic plaques •Nodulectomy is the right choice for endometriotic nodules, with the need of partial or full-thickness diaphragmatic resection according to the entity of muscular involvement. <h3>Conclusion</h3> A safe eradication of the implants requires a standardization of the surgical technique based on the knowledge of laparoscopic and histopathologic characteristics of lesions, thus avoiding intra- and post-operative morbidities.

Large Dense Periodic Arrays of Vertically Aligned Sharp Silicon Nanocones

Convex cylindrical silicon nanostructures, also referred to as silicon nanocones, find their value in many applications ranging from photovoltaics to nanofluidics, nanophotonics, and nanoelectronic applications. To fabricate silicon nanocones, both bottom-up and top-down methods can be used. The top-down method presented in this work relies on pre-shaping of silicon nanowires by ion beam etching followed by self-limited thermal oxidation. The combination of pre-shaping and oxidation obtains high-density, high aspect ratio, periodic, and vertically aligned sharp single-crystalline silicon nanocones at the wafer-scale. The homogeneity of the presented nanocones is unprecedented and may give rise to applications where numerical modeling and experiments are combined without assumptions about morphology of the nanocone. The silicon nanocones are organized in a square periodic lattice, with 250 nm pitch giving arrays containing 1.6 billion structures per square centimeter. The nanocone arrays were several mm2 in size and located centimeters apart across a 100-mm-diameter single-crystalline silicon (100) substrate. For single nanocones, tip radii of curvature < 3 nm were measured. The silicon nanocones were vertically aligned, baring a height variation of < 5 nm (< 1%) for seven adjacent nanocones, whereas the height inhomogeneity is < 80 nm (< 16%) across the full wafer scale. The height inhomogeneity can be explained by inhomogeneity present in the radii of the initial columnar polymer mask. The presented method might also be applicable to silicon micro- and nanowires derived through other top-down or bottom-up methods because of the combination of ion beam etching pre-shaping and thermal oxidation sharpening.Graphic abstractA novel method is presented where argon ion beam etching and thermal oxidation sharpening are combined to tailor a high-density single-crystalline silicon nanowire array into a vertically aligned single-crystalline silicon nanocones array with < 3 nm apex radius of curvature tips, at the wafer scale.

Defect seeded remote epitaxy of GaAs films on graphene

Remote epitaxy is an emerging materials synthesis technique which employs a 2D interface layer, often graphene, to enable the epitaxial deposition of low defect single crystal films while restricting bonding between the growth layer and the underlying substrate. This allows for the subsequent release of the epitaxial film for integration with other systems and reuse of growth substrates. This approach is applicable to material systems with an ionic component to their bonding, making it notably appealing for III–V alloys, which are a technologically important family of materials. Chemical vapour deposition growth of graphene and wet transfer to a III–V substrate with a polymer handle is a potentially scalable and low cost approach to producing the required growth surface for remote epitaxy of these materials, however, the presence of water promotes the formation of a III–V oxide layer, which degrades the quality of subsequently grown epitaxial films. This work demonstrates the use of an argon ion beam for the controlled introduction of defects in a monolayer graphene interface layer to enable the growth of a single crystal GaAs film by molecular beam epitaxy, despite the presence of a native oxide at the substrate/graphene interface. A hybrid mechanism of defect seeded lateral overgrowth with remote epitaxy contributing the coalescence of the film is indicated. The exfoliation of the GaAs films reveals the presence of defect seeded nucleation sites, highlighting the need to balance the benefits of defect seeding on crystal quality against the requirement for subsequent exfoliation of the film, for future large area development of this approach.

Elaboration and characterization of porous ultrathin gold films grown by ion beam assisted deposition

The growth of ultrathin gold layers on a silicon substrate is performed with an unconventional ion beam assisted deposition. In this setup, evaporated gold flow and ion beam flux are perpendicular. 5 and 10 nm thick gold were deposited on tilted samples with the assistance of an argon ion beam at energies of 70 and 150 eV. We explored the evolution of surface morphology, mainly roughness and porosity, with ion bombardment for two gold thicknesses. We have also extrapolated Young’s modulus of these ultrathin layers by means of high-frequency acoustic measurements in the 90–260 MHz range. We also investigated the evolution of wettability of our structures with ion bombardment as well as their electrical and optical responses.

Synthesis of superheavy elements using krypton and argon beams

Synthesis of superheavy elements using krypton and argon beams

A New Technique for Breast Pocket Adjustment: Argon Beam Thermal Capsulorrhaphy.

Summary:Implant malposition remains one of the main complications of aesthetic breast augmentation and alloplastic breast reconstruction with expanders and implants. Many capsulorrhaphy techniques have been described to adjust the breast pocket and correct the malposition. In this study, we tested the efficacy of the argon beam coagulator (ABC) for lateral capsulorrhaphy on breast reconstruction patients at the time of expander replacement with a permanent implant. We also experimentally compared the effects of the ABC and the standard electrocautery on fragments of healthy breast capsule. We noted a 69.5% capsule shrinkage with the ABC versus 46.8% with the standard electrocautery. We concluded that breast capsulorrhaphy using the ABC is a safe and efficient technique for the correction of breast implant malposition in both reconstructive and aesthetic breast surgery.

Ion-irradiation-induced effects on the surface characteristics of Ge–Bi–Se thin films

In this study, fabricated amorphous chalcogenide Ge10Se70Bi20 thin films were irradiated with nitrogen (N+), argon (Ar+), hydrogen (H+) and oxygen (O+) ion beams. The compositions of the pure and irradiated films were investigated using X-ray diffraction, which confirmed the amorphous structures of the pristine and the irradiated Ge10Se70Bi20 thin films. The optical parameters such as optical bandgap, absorption edge, Urbach energy, Tauc parameter and extinction coefficient of the unirradiated and irradiated films were determined using ultraviolet/visible spectroscopy. The energy gap was found to reduce from 1.355 eV for unirradiated Ge10Se70Bi20 to 1.02, 0.73, 0.60 and 0.51 eV after irradiation with nitrogen, argon, hydrogen and oxygen ion beams, respectively. Meanwhile, the band tail of Ge10Se70Bi20, which is 0.12 eV, increased to 0.16, 0.40, 0.45 and 0.48 eV after irradiation with nitrogen, argon, hydrogen and oxygen ion beams, respectively. In particular, the conductivity increased by two orders after the pristine film had been exposed to an oxygen beam. The direct current electrical conductivity of the pristine film increased from 1.5 × 10−7 to 1.4 × 10−5 Ω−1 cm−1 after irradiation with an oxygen ion beam. Furthermore, the activation energy and Mott’s parameters of the original and irradiated Ge10Se70Bi20 films were deduced. The reported modifications of the optical and electrical parameters suggest the use of irradiated Ge10Se70Bi20 thin films in important applications – for example, optical data storage and optoelectronic devices.

A combination of scanning electron microscopy and broad argon ion beam milling provides intact structure of secondary tissues in woody plants

The secondary tissues of woody plants consist of fragile cells and rigid cell walls. However, the structures are easily damaged during mechanical cross-sectioning for electron microscopy analysis. Broad argon ion beam (BIB) milling is commonly employed for scanning electron microscopy (SEM) of hard materials to generate a large and distortion-free cross-section. However, BIB milling has rarely been used in plant science. In the present study, SEM combined with BIB milling was validated as an accurate tool for structural observation of secondary woody tissues of two samples, living pine (Pinus densiflora) and high-density oak wood (Quercus phillyraeoides), and compared with classical microtome cross-sectioning. The BIB milling method does not require epoxy resin embedding because of prior chemical fixation and critical point drying of the sample, thus producing a three-dimensional image. The results showed that xylem structures were well-preserved in their natural state in the BIB-milled cross-section compared with the microtome cross-section. The observations using SEM combined with BIB milling were useful for wide-area imaging of both hard and soft plant tissues, which are difficult to observe with transmitted electron microscopy because it is difficult to obtain sections of such tissues, particularly those of fragile reaction woods.