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In this research, CrN coating was applied to grade 1 titanium as a bipolar plate for PEMFC. The CrN was deposited by ion beam assisted deposition (IBAD) and the arc ion plating method (AIP). The thickness of the coating layer was about 2.5∼3 μm and it was densely deposited on the titanium substrate. The electrochemical experiments were conducted in an aqueous solution of pH 3 (H2SO4 + 0.1 ppm HF, 80°C) determined by DoE. Hydrogen gas and air were bubbled to simulate the anode and cathode environments, respectively. Various analyses (XRD, EDS, FE-SEM), electrochemical experiments (EIS, potentiodynamic polarisation, potentiostatic experiment), and interfacial contact resistance measurement were performed to evaluate the effects of the PVD deposition method. Due to the difference in the PVD method, CrN and Cr2N were formed in the IBAD specimen, whereas CrN phase was observed in the AIP specimen. The CrN coated specimens presented improved interfacial contact resistance compared to the titanium substrate. [ABSTRACT FROM AUTHOR]

Hafnium oxide is widely used in optical coating materials because of its high refractive index, broad band gap, high laser damage threshold and its high transparency in the wavelength range from ultraviolet to middle infrared (0.20–12 μm). However, hafnium oxide has some defects such as strong crystallinity and poor surface quality, which results in enhanced absorption and reflection of light wave and limits its application in optical field. As a pentoxide with high transparency and excellent optical properties in the wavelength range from ultraviolet to mid-infrared(0.35–9 μm), the doping of niobium pentoxide can effectively improve the surface quality and optical properties of the films. Mixed films with different chemical compositions were prepared by ion beam assisted deposition, and the microstructure, crystallinity, surface quality, optical properties and mechanical properties of the mixed films with different chemical compositions were investigated. The doping of niobium pentoxide inhibits the crystallization of hafnium oxide, optimizes the surface quality of the films, and improves the refractive index and mechanical properties of mixed films, effectively broadens the application of hafnium oxide in the field of optical films. [ABSTRACT FROM AUTHOR]

Diamond-like carbon (DLC) has attracted significant attention in the recent decades because of its unique properties and applications. Ion beam assisted deposition (IBAD) has been widely established in industry due to the advantages of easy handling and scalability. In this work, a hemisphere dome model is specially designed as a substrate. The influence of the surface orientation on the coating thickness, Raman ID/IG ratio, surface roughness and the stress of the DLC films are examined. The reduction in the stress in the DLC films reflects the lower energy-dependence in diamond due to the varied sp3/sp2 fraction and columnar growth pattern. The variation of the surface orientation provides an efficient means of tailoring the properties and microstructure of the DLC films. [ABSTRACT FROM AUTHOR]

High quality hexagonal boron nitride (h‐BN) thick films are indispensable for practical deep‐ultraviolet (DUV) photodetector applications. However, the controllable synthesis of h‐BN films in terms of thickness and crystallinity often requires high growth temperatures, tedious chemical precursors and, catalytic transition metal substrates, that will eventually hinder their applicability. In this work, the direct growth of h‐BN films with thickness of 50–500 nm on silicon(100), sapphire, and quartz substrates by ion beam assisted deposition at a lower temperature (≈500 °C) without employing extra catalysis is reported. The as‐synthesized h‐BN thick films are stoichiometric, smooth, and continuous without obvious pinholes and cracks, consisting of nanocrystalline domains on the dielectric substrates, distinct from those grown on metallic substrates. More intriguingly, the DUV photodetector fabricated from a 500 nm thick h‐BN film on quartz substrate exhibits high peak responsivity (0.5 A W−1) with a ultrahigh on/off ratio of >103 at 204 nm, a high rejection ratio (R204nm/R250nm > 103), a large specific detectivity (6.92 × 109 Jones), and a sharp cutoff wavelength at 218 nm. The work herein demonstrates the great potential of this form of h‐BN thick films toward the development of DUV photodetectors. [ABSTRACT FROM AUTHOR]

Abstract Gold, copper and gold/copper thin layers were obtained in FIB/SEM system by Focused Ion Beam sputter deposition. Layers deposited on SiO 2 /Si and quartz substrates were subjected to Rapid Thermal Annealing (RTA) in vacuum at 1100 °C. One minute annealing of 20 nm thick films leads to formation of nanoparticles with average size of ∼20 nm but does not change the morphology of 170 nm Au and 180 nm Cu films. Implantation of Ga ions into SiO 2 /Si substrate before deposition of ∼20 nm Au layers has a strong effect on the nanostructures formed after 1 min annealing. Implantation at 30 kV for 1 and 2 min leads to formation of arbitrary shape nanoislands, which are much larger than the nanoparticles outside of the implanted region. Increase of the implantation time to 4 and 16 min leads to formation of large spheres, the size of which increases with the implantation time. The observed Ga effect is explained by the lower melting temperatures of Au/Ga and Cu/Ga binary alloys and by increased nanoparticle mobility, which favors the coalescence process. Gold nanoparticles with size of ∼20 nm obtained by RTA on control quartz substrate showed local surface plasmon resonance at 535 nm. Graphical abstract Image 1 Highlights • Gold, copper and gold/copper thin layers were obtained by focused ion beam sputter deposition in FIB/SEM system. • Au, Cu and Au/Cu nanoparticles (NPs) with average size of ∼20 nm were obtained by Rapid Thermal Annealing in vacuum at 1100 °C. • Implantation of Ga ions in SiO2/Si substrate favors the NP coalescence process leading to formation of larger nanospheres or nanoislands. • The observed Ga effect could be used to design nanopatterns. [ABSTRACT FROM AUTHOR]

A grid electrode assisted plasma based ion implantation system, which was originally designed only for ion implantation on insulator substrates, was investigated as a system of sputter deposition with high energy ion beam irradiation. When pulses of negative high voltage were applied to grid electrodes immersed in argon plasmas, high energy ions were observed to bombard the surface of the grid electrodes during the rise and plateau times of the pulses, using particle-in-cell (PIC) simulations. The resulting sputter deposition of atoms on the substrate from the stainless steel grid electrodes was confirmed by X-ray photoelectron spectroscopy. During the fall time of the pulses, PIC simulations indicated high energy ion beams of pseudowaves bombarded the surface of the substrate. Thus we verified that by using grid electrodes, ion beams can irradiate the insulator substrate after the sputter deposition within the time scale of a single pulse. In the proposed configuration, problems due to high voltage on insulator can be avoided because the insulator substrates float in plasmas for the entire process. Finally, we discuss potential application of the system for ion beam assisted deposition as a compact plasma based ion implantation and deposition system, which does not require a separate sputtering system. [ABSTRACT FROM AUTHOR]

Biaxially textured yttria stabilized zirconia (YSZ) thin films were deposited on polished hastelloy and silicon substrates using ion beam assisted deposition (IBAD). The IBAD apparatus includes a planar magnetron fitted with a crystalline YSZ target to provide the film-forming species, and two Kaufman-type ion beam sources which provide Ar + ions for bombarding the film during growth. The two ion beam sources were mounted symmetrically at 55° angles to the substrate plane normal, making 110° angle between them. Textured YSZ films were deposited under three different IBAD conditions: (a) films were bombarded by a single ion beam source (SIBAD), (b) films were bombarded by a single ion beam source for a time alternating from the two symmetric directions (AIBAD), and (c) by dual ion beam assisted deposition (DIBAD) where the film was bombarded simultaneously from the two symmetric directions. The X-ray φ-scan results indicate that DIBAD followed by epitaxial growth of YSZ produced the highest degree of biaxial texture in YSZ films. Superconducting yttrium barium copper oxide (YBCO) films deposited on highly textured DIBAD YSZ films had φ-scan full width at half maximum of 7.1° and 5.5° for hastelloy and silicon substrates, respectively. [ABSTRACT FROM AUTHOR]

Polyether ether ketone (PEEK) rods were coated via ion beam asssisted deposition (IBAD) at room temperature. The coating consists of a two-layer design of yttria-stabilized zirconia (YSZ) as a heat-protection layer, and hydroxyapatite (HA) as a top layer to increase bioactivity. A rotating substrate holder was designed to deposit an even coating on the cylindrical surface of PEEK rods; the uniformity is verified by cross-sectional measurements using scanning electron microscopy (SEM). Deposition is followed by heat treatment of the coating using microwave annealing and autoclaving. Transmission electron microscopy (TEM) showed a dense, uniform columnar grain structure in the YSZ layer that is well bonded to the PEEK substrate, while the calcium phosphate layer was amorphous and pore-free in its as-deposited state. Subsequent heat treatment via microwave energy introduced HA crystallization in the calcium phosphate layer and additional autoclaving further expanded the crystallization of the HA layer. Chemical composition evaluation of the coating indicated the Ca/P ratios of the HA layer to be near that of stoichiometric HA, with minor variations through the HA layer thickness. The adhesion strength of as-deposited HA/YSZ coatings on smooth, polished PEEK surfaces was mostly unaffected by microwave heat treatment, but decreased with additional autoclave treatment. Increasing surface roughness showed improvement of bond strength. [ABSTRACT FROM AUTHOR]

Titanium nitride nano-scale thin films have been prepared by ion beam assisted reactive DC magnetron sputtering. The films are characterized by XRD, SEM and TEM. The films are found to be amorphous. The effect of the ion beam during deposition was evident from smoothness of film surface (SEM and TEM images) and modifications in optical properties. Investigation of the optical constants shows stable refractive index dominating most of the visible range. The films are not highly absorptive in the visible range. An energy gap of 2.9 ± 0.1 eV is estimated for the IBAD amorphous titanium nitride nano-thin films. The stability of the films at normal room environment in addition to the golden color makes the nano-thin films suitable for hard and decorative coatings. [ABSTRACT FROM AUTHOR]

Single-layer and multi-layer coatings were applied on the surface of diode laser facets as mirrors. This thin film mirrors were designed, deposited, optimized and characterized. The effects of mirrors on facet passivation and optical properties of InGaAs/AlGaAs/GaAs diode lasers were investigated. High-Reflective (HR) and Anti-Reflective (AR) mirrors comprising of four double-layers of Al 2 O 3 /Si and a single layer of Al 2 O 3 , respectively, were designed and optimized by Macleod software for 944 nm diode lasers. Optimization of Argon flow rate was studied through Alumina thin film deposition by Ion Beam Assisted Deposition (IBAD) for mirror improvement. The nanostructured HR and AR mirrors were deposited on the front and back facet of the laser respectively, by IBAD system under optimum condition. Atomic Force Microscope (AFM), Vis-IR Spectrophotometer, Field Emission Scanning Electron Microscopy (FESEM) and laser characterization Test ( P – I ) were used to characterize various properties of mirrors and lasers. AFM images show mirror’s root mean square roughness is nearly 1 nm. The Spectrophotometer results of the front facet transmission and the back facet reflection are in good agreement with the simulation results. Optical output power ( P ) versus driving current ( I ) characteristics, measured before and after coating the facet, revealed a significant output power enhancement due to optimized AR and HR optical coatings on facets. [ABSTRACT FROM AUTHOR]

Epitaxial films have a variety of important applications including semiconducting and superconducting devices. However, the application of epitaxy is typically limited by the necessity of single-crystal substrates. An alternative substrate technology is to artificially create a biaxially (out-of-plane and in-plane) oriented layer and use that template as the substrate for epitaxy. Here we review ion-beam assisted deposition (IBAD) methods for inducing biaxial crystal alignment during film deposition. In this review we present a historical overview of IBAD texturing and a status of understanding of IBAD texturing. A number of materials have been demonstrated to exhibit IBAD biaxial texturing. IBAD texturing of MgO is the most attractive ion texturing process today because of the high degree of alignment and because of how quickly this alignment develops. MgO texture evolution can be separated into three different regions. During initial IBAD an amorphous layer is formed, followed by onset of biaxial texture that appears in the first 1–2 nm of film deposit. Texture then improves with continued IBAD. Still further texture improvement is seen with growth of epitaxial overlayers without an ion beam, as the grains grow larger. In the best cases reported the mosaic spreads of epitaxial films on IBAD substrates have full width half maxima of less than 1°. The biaxially ordered films produced by IBAD make good templates for subsequent heteroepitaxial growth of functional layers if they are appropriately lattice matched, thus eliminating the need for single crystal substrates. We discuss applications of these artificially crystal-aligned films as substrates for energy applications such as for superconductors and photovoltaics. [ABSTRACT FROM AUTHOR]

Antimonide cobalt thin films were deposited on BK7 glass substrates at various substrate temperatures by ion beam sputtering deposition with a fan-shape target. The influence of deposition temperature on the microstructure and thermoelectric properties of antimonide cobalt thin films were systematically investigated. It is found that the Seebeck coefficient of the thin film increases at first and then decreases with the increasing deposition temperature. The Seebeck coefficient of the sample deposited at 250 °C has maximum value and increases stably when the measuring temperature increased from room-temperature to 600 K. The electrical conductivity of the thin film increases significantly to 5.6 × 10 4 S cm −1 when the deposition temperature was 450 °C and then decreases greatly when the temperature increased to 500 °C and 550 °C. The behavior of electrical conductivity of the sample deposited at 250 °C changes from metallic to semiconducting after the measuring temperature exceeded 540 K. The power factor of antimonide cobalt thin film deposited at 250 °C has a maximum value of 0.93 × 10 −4 W m −1 K −2 at room-temperature and then increases to 3.5 × 10 −4 W m −1 K −2 when the measuring temperature was 540 K. [ABSTRACT FROM AUTHOR]

Lithium phosphorus oxynitride (LiPON) solid state amorphous film electrolytes were synthesized by ion beam assisted deposition (IBAD) using Li 3 PO 4 target under nitrogen reactive plasma. IBAD presents an advantage of controllable nitrogen content of the films by adjusting N 2 and Ar flow ratio. X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), nanoindenter, and profiler were employed to characterize LiPON films. Our results indicate that the film at N 2 and Ar flow ratio of 1:8 showed the best surface morphology and mechanical properties. The highest N atomic percentage of 2.32% was also obtained at this synthesis circumstance, and the resultant LiPON film electrolyte showed higher ionic conductivity of 4.5 × 10 −6 S/cm at room temperature, as well as the highest hardness of 6.8 GPa and the lowest compressive stress of 147.2 MPa. It is believed that as-prepared LiPON solid state electrolyte film optimized can effectively prevent delamination from electrodes, showing some promising application in thin film lithium ion batteries. [ABSTRACT FROM AUTHOR]

Highlights: [•] Nanohardness of the TiAlN/Ta multilayer film was 29% higher than that of the TiAlN monolayer film. [•] Compared to the TiAlN monolayer film, a 47% increase of elastic modulus was achieved. [•] Bonding strength of the TiAlN/Ta multilayer film was higher than that of the TiAlN monolayer film. [•] The TiAlN/Ta multilayer film has better thermal stability than the TiAlN monolayer film. [ABSTRACT FROM AUTHOR]

Abstract: In this study, it was found that uniquely ordered lattice field favors transport of carriers but hinder that of phonons. The n-Bi2Se0.5Te2.5 pillar array film was successfully achieved by a simple ion beam assisted deposition technique. This oriented pillar array structure is clear with pillar diameter of about 30nm, exhibiting a uniquely ordered lattice field. The properties of the ordered Bi2Se0.5Te2.5 pillar array were greatly enhanced in comparison with those of the ordinary film. The Bi2Se0.5Te2.5 pillar array with a thermoelectric dimensionless figure-of-merit ZT=1.28 was obtained at room temperature. The in-plane transport mechanisms of the ordered pillar array and the ordinary structures, lattice field model, are proposed and investigated. The specially ordered lattice field is the main reason for the properties enhancement observed in the Bi2Se0.5Te2.5 film. Introduction of such ordered lattice field into TE films is therefore a very promising approach. [Copyright &y& Elsevier]

Both the structure and the type of the nucleation surface play a key role in texture development of IBAD MgO films. We have examined these features in Al2O3 and Y2O3 thin films using two different types of deposition methods, atomic layer deposition (ALD) and electron beam evaporation (EBE). Examination of EBE Al2O3 with in situ reflected high-energy electron diffraction (RHEED) films reveals the presence of a nanocrystalline structure that remains unchanged after and is insensitive to ion irradiation with 750 eV argon ions. In contrast, ALD Al2O3 examined with the same method reveals a featureless image that appears amorphous. Use of the ALD Al2O3 film can result in well-textured films with reasonable in-plane mosaic spread values (\sim 14^\circ) without process optimization. Similar results were obtained on ALD and EBE Y2O3 films, although, the EBE Y2O3 appeared amorphous in the RHEED even before exposure to the ion beam. The ALD Y2O3 film resulted in an in-plane texture of \sim 10^\circ. Finally, bare silicon substrates were examined. It was found that even with the native oxide remaining on its surface, the silicon underneath was amorphized by the ion beam and provided a suitable surface for the deposition of biaxial textured MgO with an in-plane texture of \sim 7^\circ FWHM. [ABSTRACT FROM AUTHOR]

The article focuses on a study which examined the growth of biaxially orienbted yttria-stabilized zirconia (YSZ) buffer layers on amorphous substrates via pulsed laser deposition (PLD) and ion-beam assisted laser deposition (IBLAD). Particular focus is given to the results of X-ray Bragg-Brentano scans on a set of buffer layers. Topics discussed include assisting ion-beam quality, crystal structure of the YSZ film, and diffraction patterns.

Anisotropic damage tolerance is examined in relation to the in-plane orientations of [200] biaxially aligned yttria-stabilized zirconia (YSZ) films fabricated using dual ion beam deposition and ion beam assisted electron beam deposition. It is shown that ion channeling and anisotropic ion etching are not associated with IBAD biaxial alignment. The mechanism of IBAD biaxial alignment is crystallographic orientation change to reduce ion damage. The aggregation of defects leads to the formation of low angle grain boundaries that enable the growth direction change. Damage-tolerant crystalline planes are aligned in the direction of the assisting ion beam through the growth direction change. [ABSTRACT FROM PUBLISHER]

• Ion beam bombardment improves Zn-Sb films' quality. • Voltage and current of the ion beam alter the structural phase. • Zn-Sb films with mixed phase show best thermoelectric properties. Zn-Sb alloys are potential low-cost and non-toxic p-type thermoelectric materials for applications in the temperature range between 300 and 700 K. In this experiment, Zn-Sb alloy films were prepared by electron beam evaporation through an ion beam assisted deposition (IBAD). Our studies have confirmed that the structural phase, chemical composition, chemical binding, carrier concentration and microstructures of the film can indeed be effectively controlled by the voltage and current of the ion beam. Particularly, the carrier concentration of the film will rise along with the increase of the argon ion beam current. When the ion beam currents are set at 0.2–0.6 A, the carrier concentrations of the films can be controlled at around 1019–1020 cm−3, which fall within the optimal carrier concentration range for Zn-Sb based thermoelectric materials. The temperature dependence of Seebeck coefficient and the electrical conductivity of the films were measured to evaluate their thermoelectric performance. The results indicate that the film with Zn 4 Sb 3 + ZnSb mixed phase will have better thermoelectric properties. A high power factor value of ~1280 μW/m-K2 is obtained in the films assisted by the ion beam current of 0.6 A. Our results demonstrate that the IBAD technique is extraordinary promising to fabricate Zn-Sb films with excellent thermoelectric performance and can be used to produce other potential thermoelectric materials. [ABSTRACT FROM AUTHOR]