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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]

A method for generating high quality multilayer blazed gratings using ion beam assisted deposition is proposed and analyzed with numerical simulations. Conventional fabrication methods for multilayer blazed gratings are limited by unwanted smoothing of the surface profile during multilayer deposition. By contrast, we demonstrate that our proposed method is capable of producing gratings that retain a nearly ideal blazed grating profile after the deposition of an arbitrary number of layers. Through numerical analysis, we establish the conditions in which this procedure produces a high quality multilayer blazed grating. These gratings would be suitable for use in the extreme ultraviolet or soft X-ray regime. We also discuss how the control parameters may be selected to optimize the gratings formed in an experiment. [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]

Nano-columnar arrays of Cu2O were grown by the oblique angle sputter deposition technique based on the self-shadowing principle. The as-grown nano-columnar samples are oriented along {111} direction, and they are highly transmitting in the visible range with a low reflectance. In this work, we show the photo-electrochemical activity of nano-columnar array of Cu2O, which shows a higher (~25%) photocurrent density and a two-fold enhancement in the incident-to-photon conversion efficiency as compared to continuous thin film of Cu2O in photo-assisted proton reduction type reaction. The improvement in electrochemical activity of nano-columnar Cu2O photocathode can be attributed to the change in morphology, crystal structure, as well as electrical property, which shows a higher degree of band bending, increased donor carrier (e-) density and lower width of space charge region as revealed by capacitance measurements and Mott-Schottky analysis. [ABSTRACT FROM AUTHOR]

Iron oxide films were produced using ion-beam-assisted deposition, and Raman spectroscopy and x-ray diffraction indicate single-phase magnetite. However, incorporation of significant fractions of argon in the films from ion bombardment is evident from chemical analysis, and Fe/O ratios are lower than expected from pure magnetite, suggesting greater than normal disorder. Low temperature magnetometry and first-order reversal curve measurements show strong exchange bias, which likely arises from defects at grain boundaries, possibly amorphous, creating frustrated spins. Since these samples contain grains ~6 nm, a large fraction of the material consists of grain boundaries, where spins are highly disordered and reverse independently with external field. [ABSTRACT FROM AUTHOR]

A series of ferromagnetic Ni80Fe20(55 nm)/antiferromagnetic CoO (25 to 200 nm)/ferromagnetic Co (55 nm)/SiO2(substrate) trilayer thin films were fabricated by ion-beam assisted deposition in order to understand the role of ion beam modification on the interfacial and interlayer coupling. The microstructural study using transmission electron microscopy, X-ray reflectometry, and polarised neutron reflectometry showed that ion-beam modification during the deposition process led to an oxygen-rich Co/CoO nanocomposite interface region at the bottom layer. This interface caused a high exchange bias field for the ferromagnetic cobalt. However, the exchange bias for top permalloy ferromagnet remained low, in line with expectations from the literature for the typical interfacial energy. This suggest that the ion-beam enhancement of the magnetic exchange bias is localized to the Co/CoO interface where local microstructural effects provide the dominant mechanism. [ABSTRACT FROM AUTHOR]

FeAl films around equiatomic composition are grown on a-cut (1120) sapphire substrates by ion beam assisted deposition (IBAD) and pulsed laser deposition (PLD) at ambient temperature. Subsequent successive annealing is used to establish chemical order and crystallographic orientation of the films with respect to the substrate. We find a strongly [110]-textured growth for both deposition techniques. Pole figures prove the successful preparation of high quality epitaxial films by PLD with a single in-plane orientation. IBAD-grown films, however, exhibit three in-plane orientations, all of them with broad angular distributions. The difference of the two growth modes is attributed to the existence of a metastable intermediate crystalline orientation as concluded from nonassisted sputter depositions at different substrate temperatures. The formation of the chemically ordered crystalline B2 phase is accompanied by the expected transition from ferromagnetic to paramagnetic behavior of the films. In accordance with the different thermally induced structural recovery, we find a step-like magnetic transition to paramagnetic behavior after annealing for 1 h at TA = 300 °C for IBAD deposition, while PLD-grown films show a gradual decrease of ferromagnetic signals with rising annealing temperatures. [ABSTRACT FROM AUTHOR]

An antiferromagnetic-IrMn-based giant-magnetoresistance spin-valve (GMR-SV) multilayer on a high-temperature superconductor YBa2Cu3O7−x (YBCO) film was prepared using an ion-beam deposition system. The exchange bias coupling field (Hex), coercivity (HC), and magnetoresistance ratio (MR (%)) of the hybrid YBCO/GMR-SV multilayer structure were measured and compared at room temperature and 77 K. The MR ratio (%) of the hybrid YBCO/GMR-SV structure measured by the four-probe method at 77 K was − 9.3%, different from that of the conventional GMR-SV structure. The phenomenon of a negative MR (%) below the critical temperature (Tc) can be explained by the current-in-plane tunneling effect, when the resistance of the middle gap (G) layer between the high-temperature superconductor YBCO and GMR-SV multilayer reaches a value comparable to the plane resistance of the upper metal layer. In order to analyze the inversed MR (%) of the hybrid YBCO/GMR-SV multilayer structure, the equivalent circuit for each layer was constructed and an equation of the output voltage was derived. [ABSTRACT FROM AUTHOR]

Abstract A series of Ni 80 Fe 20 /poly(3-hexylthiohene) (P3HT)/Fe organic spin valves (OSVs) have been prepared by ion beam assisted deposition combined with spin coating technique. A negative magnetoresistance (MR) with the value of 0.08% at room temperature is observed, exhibiting an inverse spin-valve effect, indicating that the MR behavior in Ni 80 Fe 20 /P3HT/Fe spin valve is distinctive and different from that in the Co-based P3HT spin valves. After increasing the bombarding energy of the top electrode, an additional positive MR is observed at low magnetic field range. By comparing with the MR under different relative direction of electric current and magnetic field in P3HT/Fe bilayers, the positive MR observed in OSVs is attributed to the anisotropic magnetoresistance (AMR) of the Fe/P3HT interfacial layer. These experimental results demonstrate that the interfacial layer plays an important role in the MR behavior of OSVs. On one hand, the interfacial layer adjusts the electronic structure to induce the inverse spin-valve effect; on the other hand, it affects the magnitude of MR. These results can help us understand the role of the interactions between organic semiconductors and metal electrodes in the organic spintronic systems. Highlights • An inverse spin-valve effect in Ni 80 Fe 20 /P3HT/Fe spin valve was observed. • The value of MR of Ni 80 Fe 20 /P3HT/Fe spin valve is around 0.08% at the room temperature. • Two types of MR were observed after increasing the Fe deposition energy. • The positive MR in spin valve can be attributed to AMR of Fe/P3HT interlayer. [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]

SnO x films were fabricated on soda-lime glass and sapphire substrates by reactive ion beam sputter deposition (IBSD). A detailed growth series on c -plane sapphire was prepared using heater temperatures from room temperature to 600 ° C with different oxygen-to-argon ratios to investigate the impact of those parameters on thin film characteristics. By applying X-ray diffraction analysis and Raman spectroscopy an operating window was defined, in which SnO was grown without inclusions of parasitic Sn-related phases. The chemical bonding of the films was examined by X-ray photoelectron spectroscopy (XPS). Only a very narrow regime of oxygen flux was found with a composition close to stoichiometry. Furthermore, variation of the composition in SnO 1 ± δ as well as the growth temperature were found to influence the morphology of the grown layer. The surface morphology was investigated by scanning electron microscopy (SEM) and atomic force microscopy (AFM). An average grain size of ≈ 10 –50 nm was revealed for films grown at 200 ° C, which increases for annealed samples and samples grown at elevated temperatures. In addition to the expected influence on grain growth and surface roughness, disintegration of the SnO crystallites was found for inappropriate oxygen flux and heater temperature, giving way to incorporation of Sn or SnO 2 species. [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]

X-ray mirrors are widely used in advanced x-ray facilities. An ellipsoidal mirror is used in soft x-ray focusing optics. To prevent a decrease in the intensity density or distortion of the wavefront of reflected x-ray beams, the inner surface of an ellipsoidal mirror should have high precision. Differential deposition is a method of fabricating a shape on a mirror surface. However, mirrors with a small diameter cannot be corrected by the conventional process. In this study, a figure correction method employing ion beam sputtering deposition was developed. The sputtering target is placed inside the ellipsoidal mirror. Then, a cylindrical tube with a small aperture is inserted inside the mirror to realize selective deposition. The figure accuracy of an ellipsoidal mirror is improved even when its diameter is less than 10 mm. This figure correction system can also be applied to various axisymmetric devices with a small diameter. [ABSTRACT FROM AUTHOR]

In this study, the authors have demonstrated that it is possible to realize several three-dimensional (3D) micro- and nanostructures, by the fabrication of the smallest microhouse using a dual beam scanning electron microscope (SEM)/focused ion beam (FIB) Auriga 60 from Zeiss together with a six degree of freedom robot built with SmarAct components. In this new type of nanolab, cutting, etching, folding, assembling, and then welding thin membranes of silica on top of a cleaved optical fiber SMF28, or production of micro- and nanostructures, like the microhouse, are possible. The authors have experimentally shown that FIB can be used, in this new generation of micro/nanofactory, in combination with SEM, and gas injection system, in order to fabricate three-dimensional microstructures: a microhouse in this study, with ultrahigh accuracy assembly down to 10 nm. By using the theory of sputtering, the authors are able to propose a model of folding thin membranes of numerous materials such as metals, polymers, or crystals, i.e., silica, silicon, potassium tantalite, or lithium niobate. This method is usually described as origami in the literature [W. J. Aroa, H. I. Smith, and G. Barbastathis, Microelectron. Eng. 84, 1454 (2007); W. J. Aroa et al., J. Vac. Sci. Technol., B 25, 2184 (2007); and K. Chalapat et al., Adv. Mater. 25, 91 (2013)]. The experimental results indicate that the introduction of a microrobot inside the SEM vacuum chamber will provide the means to enlarge the scope of clean room facilities to build complex and smart 3D microsystems with heterogeneous materials, especially on the facet of an optical fiber in the lab on fiber new field. The authors propose a new way to easily manufacture many kinds of optical functions for light trapping based on nanoantennas, nanophotonic crystal, axicon or lattice, 3D biosensor with origami, and nanopatterning surfaces or carbon nanotubes, etc. [ABSTRACT FROM AUTHOR]

TiAlSiN coatings were deposited on Si substrates by ion beam-assisted deposition. The oxidation resistance and mechanism of TiAlSiN at 800°C, 900°C, and 1000°C under a nitrogen atmosphere were discussed and compared with those of TiAlSiN under argon and air atmospheres. The microstructure, bonding characteristics, and phase transition of the coatings were systematically investigated. The results indicated that nitrogen atmosphere effectively inhibited oxidation of the TiAlSiN coatings. The key reason for this improvement was that nitrogen maintained Ti-N and Si-N chemical bonds, and a dense Al2O3 layer was much more easily generated under the nitrogen atmosphere. We used first-principles calculations to investigate the electronic structures and bonding characteristics of TiAlSiN in this work. [ABSTRACT FROM AUTHOR]

The thermal dissolution and decarburization of WC-based powders that occur in various spray processes are a widely studied phenomenon, and mechanisms that describe its development have been proposed. However, the exact formation mechanism of decarburization products such as metallic W is not yet established. A WC-17Co coating is sprayed intentionally at an exceedingly long spray distance to exaggerate the decarburization effects. Progressive xenon plasma ion milling of the examined surface has revealed microstructural features that would have been smeared away by conventional polishing. Serial sectioning provided insights on the three-dimensional structure of the decarburization products. Metallic W has been found to form a shell around small splats that did not deform significantly upon impact, suggesting that its crystallization occurs during the in-flight stage of the particles. W2C crystals are more prominent on WC faces that are in close proximity with splat boundaries indicating an accelerated decarburization in such sites. Porosity can be clearly categorized in imperfect intersplat contact and oxidation-generated gases via its shape. [ABSTRACT FROM AUTHOR]

One of the many challenges for niobium (Nb) based superconducting devices is the concurrent improvement over the surface morphology without undermining superconducting properties. In this work, the authors demonstrated the modification to the surface morphology of 10–100 nm Nb thin films deposited by bias target ion beam deposition (BTIBD). Target current (IT) and target bias (VT) were the main parameters explored and were found to be critical to the control over crystallinity and surface morphology of Nb films. The optimized growth conditions yielded a ∼50 nm thick Nb film with the root-mean-square roughness of 0.4 nm, which was an order of magnitude smoother than that of Nb films by sputtering process. The critical temperature for superconductivity was close to the value of the bulk Nb (∼9.3 K) with a very homogeneous transition (the superconducting transition width ΔTc of 0.1 K). The quality of Nb film was evident in the presence of a very thin proximity layer (∼0.75 nm). The experimental results demonstrated that the preparation of smooth Nb films with expected superconductivity by BTIBD could serve as a base electrode for the in situ magnetic layer or insulating layer for superconducting electronic devices. [ABSTRACT FROM AUTHOR]

Coating uniformity is critical in fabricating high-performance optical filters by various vacuum deposition methods. Simple and planetary rotation systems with shadow masks are used to achieve the required uniformity [J. B. Oliver and D. Talbot, Appl. Optics 45, 13, 3097 (2006); O. Lyngnes, K. Kraus, A. Ode and T. Erguder, in 'Method for Designing Coating Thickness Uniformity Shadow Masks for Deposition Systems with a Planetary Fixture', 2014 Technical Conference Proceedings, Optical Coatings, August 13, 2014, DOI: http://dx.doi. org/10.14332/svc14.proc.1817.]. In this work, we discuss the effect of rotation pattern and speed on thickness uniformity in an ion beam sputter deposition system. Numerical modeling is used to determine statistical distribution of random thickness errors in coating layers. The relationship between thickness tolerance and production yield are simulated theoretically and demonstrated experimentally. Production yields for different optical filters produced in an ion beam deposition system with planetary rotation are presented. Single-wavelength and broadband optical monitoring systems were used for endpoint monitoring during filter deposition. Limitations of thickness tolerances that can be achieved in systems with planetary rotation are shown. Paths for improving production yield in an ion beam deposition system are described. [ABSTRACT FROM AUTHOR]

Ytterbium fluoride (YbF3) single thin films were prepared on sapphire and monocrystalline silicon substrates through conventional thermal evaporation and ion beam-assisted deposition (IAD), at bias voltages ranging from 50 to 160 V of the Leybold advanced plasma source (APS). By using the Cauchy dispersion model, the refractive index and thickness of the YbF3 thin films were obtained by fitting the 400-2500 nm transmittance of the monolayer YbF3 thin films on the sapphire substrate. At the same time, the refractive index and thickness of the YbF3 thin films on the monocrystalline silicon substrates were also measured using the VASE ellipsometer at wavelength from 400 to 2200 nm. The results showed that the refractive index deviation of the YbF3 thin films between the fitted values by the transmittance spectra and the measured values by the VASE ellipsometer was <0.02 and the relative deviation of the thickness was <1%. Furthermore, the refractive index of the YbF3 thin films increased with increasing APS bias voltage. The conventional YbF3 thin films and the IAD thin films deposited at low bias voltage revealed a negative inhomogeneity, and a higher bias voltage is beneficial for improving the homogeneity of YbF3 thin films. [ABSTRACT FROM AUTHOR]

Transparent conductive NiO thin films with 18 at% Cu dopant were fabricated by ion beam assisted deposition (IBAD). Their structural and optoelectronic properties were compared with undoped NiO films and NiO films doped with 12 at% Cu, and also compared with NiO:Cu (18 at%) films deposited by RF sputtering as reported in our previous work. The results show that the crystallinity of NiO thin films deposited through IBAD technology is much better than that of the films deposited by RF sputtering. Thanks to this reason, the highest carrier mobility above 45 cm 2 V −1 s −1 for NiO:Cu (18 at%) film can be realized here. Meanwhile, the films’ resistivity remains an acceptable value, varying from 2.05 to 0.064 Ω cm with oxygen ion beam current changing from 0.2 to 0.8 A. This feature is imperative for p-type transparent conductive oxides (TCOs) applied in various domains. In addition, with oxygen ion beam current increase, the increase of the Ni 3+ /Ni 2+ ratio leads to more Ni 2+ vacancies be introduced into NiO films, which is beneficial to generate holes and improve carrier concentration. In this work, the optimal carrier mobility of NiO film doped with 18 at% Cu is obtained when the oxygen ion beam current is 0.2 A. Its carrier concentration and electrical resistivity are 7.26 × 10 16 cm −3 and 2.05 Ω cm, respectively. [ABSTRACT FROM AUTHOR]

SnO2 thin films were grown on (0001) (c‐plane), ( 01 1 ¯ 2 ) (r‐plane), ( 11 2 ¯ 0 ) (a‐plane) and ( 10 1 ¯ 0 ) (m‐plane) sapphire substrates using ion beam sputter deposition (IBSD) of a pure metallic Sn target at a constant gas mixture of 2.5 sccm argon and 15 sccm oxygen at 550 °C substrate temperature. X‐ray diffraction in Bragg–Brentano geometry revealed that SnO2 film deposited on each substrate is grown with preferential out‐of‐plane orientation. The determined orientation relationships were SnO2 ( 100 ) ∥ Al2O3 (0001) (c‐plane), SnO2 ( 101 ) ∥ Al2O3 ( 11 2 ¯ 0 ) (a‐plane), SnO2 ( 101 ) ∥ Al2O3 ( 01 1 ¯ 2 ) (r‐plane) and SnO2 ( 002 ) ∥ Al2O3 ( 10 1 ¯ 0 ) (m‐plane). X‐ray diffraction (XRD) proved epitaxial growth, perceivable by very narrow full width at half maximum (FWHM) in rocking curves and Laue oscillations in standard Θ–2Θ Bragg–Brentano scans. X‐ray pole figures even revealed epitaxial in‐plane relationships. [ABSTRACT FROM AUTHOR]

Surface modification treatments able to confer antistain/antibacterial properties to natural or synthetic materials are receiving increasing attention among scientists. Ion beam co-sputtering (IBS) of zinc oxide (ZnO) and poly-tetrafluoroethylene (PTFE) targets allows for the preparation of novel multifunctional coatings composed of antimicrobial ZnO nanoparticles (NPs) finely dispersed in an antistain PTFE polymeric matrix. Remarkably, IBS has been proved to be successful in the controlled deposition of thin nanocoatings as an alternative to wet methods. Moreover, tuning IBS deposition parameters allows for the control of ZnONP loadings, thus modulating the antibacterial/antistain coating's final properties. All the deposited coatings were fully characterized by X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and transmission electron microscopy (TEM) in order to obtain information on the materials' surface composition, with deep insight into the nanocoatings' morphology as a function of the ZnONP loadings. An analysis of high-resolution XP spectra evidenced a high degree of polymer defluorination along with the formation of inorganic fluorides at increasing ZnO volume ratios. Hence, post-deposition treatments for fluorides removal, performed directly in the deposition chamber, were successfully developed and optimized. In this way, a complete stoichiometry for inorganic nanophases was obtained, allowing for the conversion of fluorides into ZnO. [ABSTRACT FROM AUTHOR]

The results of experimental studies of the Pt structure with the thickness ranging from (0.48 ± 0.1) to (24.38 ± 0.1) nm ion beam including deposition by focused ion beam are presented. The rate of ion beam including deposition of Pt, which depending on the modes varies from (0.28 ± 0.02) to (6.7 ± 0.5) nm/s, is determined experimentally. The deviation of Pt lateral structure sizes from those preset by the template decreases from (29.3 ± 0.07)% to (2.4 ± 0.2)% depending on the deposition duration. By the thicknesses of Pt nanosized structures larger than 3 nm, their specific resistance amounts to (23.4 ± 1.8) Ohm cm and weakly depends on the thickness. The results can be used for developing the technological processes used to form the structures of microelectronics sensorics, nanoelectronics, and nano- and microsystem engineering. [ABSTRACT FROM AUTHOR]

This paper presents properties of a-C:H:Si coatings as a function of incorporated silicon atoms. The chemical composition of the examined coatings was controlled by tetramethylsilane (Si(CH 3 ) 4 ) to methane (CH 4 ) flow ratio during RF PECVD (Radio Frequency Plasma Enhanced Chemical Vapour Deposition) process conducted at two values of negative substrate bias. The results have shown two stages in behavior of hardness, refractive index and density of deposited coatings, measured using the nanoindentation, ellipsometry and X-ray reflectivity techniques, respectively. The critical concentration of incorporated silicon, dividing the two stages, was established to about 15 at.%. Below this concentration the analyzed parameters decrease with the increasing amount of dopant, whereas above this value, just after reaching the minimum, further increase in silicon concentration results in increase of hardness, refractive index and density. We also registered a high consistency of results from both ellipsometry and X-ray reflectivity methods. [ABSTRACT FROM AUTHOR]

Amorphous carbon and hydrogenated amorphous carbon layers were implanted at room temperature with Co ions to investigate the role of hydrogen on the Co distribution. Amorphous carbon (a:C) and hydrogenated amorphous carbon (a:C–H) films were prepared by mass selective ion beam deposition with a 5 kV acceleration voltage using C + and C 3 H 6 + ions, respectively. The typically 100 nm thin films were implanted with Co using a 30 kV acceleration voltage to a fluence of 4 × 10 16 cm −2 . Raman measurements showed that Co implantation in hydrogenated amorphous carbon causes increased sp 2 clustering while in amorphous carbon there is significant rehybridisation of carbon from sp 3 to sp 2 bonding. High resolution Rutherford backscattering measurements indicated that in the absence of hydrogen in the base matrix, the implantation profile assumes a unimodal distribution as predicted by simulations. However, in the presence of hydrogen the effects of collision cascade enhanced diffusion are significant in altering the implantation profile resulting in a bimodal distribution. The difference in the Co depth distribution between a:C and a:C–H films is explained by the change in thermal conductivity of the carbon matrix in the presence of hydrogen. The ability to position Co (magnetic atoms) in the surface region of diamond-like carbon films offers great advantages for applications in novel magnetic devices. [ABSTRACT FROM AUTHOR]

We report here XPS study of AlN thin films grown on Si(100) substrates at different temperatures by ion beam sputter deposition (IBSD) under reactive assistance of N + /N 2 + ions. The compositional variations on their surface as well as at a depth of 50 nm beneath the surface are presented and discussed. The temperature of the substrate was varied as room temperature (RT), 100 °C and 500 °C. The binding energy of Al-2p, N-1s and O-1s core level electrons indicated formation of 2H polytypoid of AlN. The increase in concentration of AlN with substrate temperature during deposition is elucidated through a detailed analysis of calculated elemental atomic concentrations (at. %) of all possible phases present at the film surface as well as beneath the surface. Our results show predominant formation of AlN as high as 74.0 at. % on the surface and 89.0 at. % at a depth of 50 nm beneath the surface is achieved by using the substrate temperature as a deposition process variable. This high phase fraction of AlN in thin film surface is significant when compared to other growth techniques. In addition, simultaneous formation of stoichiometrically different phases could be established from measurement of element concentrations. [ABSTRACT FROM AUTHOR]

In this study, high-aspect ratio silicon nanowire (SiNW) – modified atomic force microscopy (AFM) probes are fabricated using focused ion beam (FIB) microfabrication technology and vapor-solid-solid synthesis. Commercially available soft silicon nitride probes are used for localized nanowire growth yielding soft high-aspect ratio AFM probes. The SiNW-modified cantilevers are used here for imaging in PeakForce Tappingۛ (PFT) mode, which offers high force control along with valuable information about tip-sample adhesion. A platinum catalyst, deposited accurately at a truncated AFM tip by ion beam-induced deposition (IBID), was used for localized nanowire synthesis. It could be shown that the deposition of a thin silicon dioxide layer prior to the catalyst deposition resulted in controlled SiNW growth on silicon as well as silicon nitride probes. In addition, a FIB-based method for post-growth alignment of the fabricated SiNW tips is presented, which allows tilt-compensation specifically tailored to the specifications of the used AFM instrumentation. To demonstrate the capability of such soft, high-aspect ratio AFM probes, optical gratings fabricated in GaAs and silver halide fibers were imaged in PFT mode. Additionally, the mechanical stability of these high-aspect AFM probes was evaluated on a sapphire substrate. [ABSTRACT FROM AUTHOR]

The assistance of thin film deposition with low-energy ion bombardment influences their final properties significantly. Especially, the application of so-called hyperthermal ions (energy <100 eV) is capable to modify the characteristics of the growing film without generating a large number of irradiation induced defects. The nitrogen ion beam assisted molecular beam epitaxy (ion energy <25 eV) is used to deposit GaN thin films on (0001)-oriented 6H-SiC substrates at 700 °C. The films are studied in situ by reflection high energy electron diffraction, ex situ by X-ray diffraction, scanning tunnelling microscopy, and high-resolution transmission electron microscopy. It is demonstrated that the film growth mode can be controlled by varying the ion to atom ratio, where 2D films are characterized by a smooth topography, a high crystalline quality, low biaxial stress, and low defect density. Typical structural defects in the GaN thin films were identified as basal plane stacking faults, low-angle grain boundaries forming between w-GaN and z-GaN and twin boundaries. The misfit strain between the GaN thin films and substrates is relieved by the generation of edge dislocations in the first and second monolayers of GaN thin films and of misfit interfacial dislocations. It can be demonstrated that the low-energy nitrogen ion assisted molecular beam epitaxy is a technique to produce thin GaN films of high crystalline quality. [ABSTRACT FROM AUTHOR]

Titanium nitride is regarded as an alternative plasmonic material for its tunability and other high performances. In this work, we prepared $$\hbox {TiN}_{x}$$ thin films by ion beam assisted deposition and studied the effects of assisting ion energy $$E_\mathrm{a}$$ on the structural, electrical, optical, and plasmonic properties of the films. The results show that the bombardment of assisting ions causes higher crystallinity and higher resistivity. Both the experimental and fitting results show that assisting ions can improve the plasmonic performance of $$\hbox {TiN}_{x}$$ thin films. Higher $$E_\mathrm{a}$$ leads to lower carrier concentration, lower plasma frequency, and lower optical losses. With $$E_\mathrm{a}$$ increasing, the energy loss function shifts toward low photon energy. Importantly, IBAD- $$\hbox {TiN}_{x}$$ can serve as a promising plasmonic material in visible and near-IR region, and its plasmonic properties can be effectively tuned by assisting ions energy. [ABSTRACT FROM AUTHOR]

A novel metal–dielectric stacks coating of Cu/Zr 0.2 Al 0.8 N/ZrN/AlN/ZrN/AlN/Al 34 O 62 N 4 as the solar selective absorbing coating was designed. Thin films of Zr 0.2 AlN 0.8 , ZrN, AlN and Al 34 O 62 N 4 deposited by the dual ion beam assisted deposition (DIBAD) were investigated by X-ray diffraction and spectroscopic ellipsometry. XRD results indicate the deposited films of Zr 0.2 Al 0.8 N, AlN, and Al 34 O 62 N 4 are poorly crystallized, whereas, the ZrN film is polycrystalline. The Drude-type dispersion model and Tauc–Lorentz dispersion model are used for determining the complex refractive indices of ZrN and Zr 0.2 Al 0.8 N, respectively. For Al 34 O 62 N 4 and AlN films, Cauchy’s dispersion formula is employed to determine their optical constants. A seven-layer stack with alternating ZrN and AlN layers is optimized by optical simulation programme of TFCalc. The optimized coating obtains the solar absorptance of 0.942 and the emittance of 0.12 at 100 °C. [ABSTRACT FROM AUTHOR]

We present a detailed study of sub-bandgap losses in TiO 2 optical coatings prepared by using a single and a dual ion beam deposition. By extracting high-precision spectra of the losses in the TiO 2 layers deposited under varied parameters we were able to study the losses in great detail. We were able to identify several spectral features and discuss their origin. Additional experiments allowed us to determine the contribution of absorption and scattering to the losses, as well as to discern whether the observed losses have volume or interface character. The results reveal that the dominant source of absorption in the high-quality samples is volume absorption originating from the so-called Urbach tail. We discuss the limitations imposed by the Urbach tail. [ABSTRACT FROM AUTHOR]

Dual-Ion Beam Assisted Deposition is a suitable method for the preparation of giant magneto-impedance (GMI) materials. In this paper, Co 73 Si 12 B 15 thin films with different thicknesses were prepared by Dual-Ion Beam Assisted Deposition, and the influences of film thickness on magnetic properties and GMI effect were investigated. It was found that the asymmetric magnetic hysteresis loop in the prepared Co 73 Si 12 B 15 thin films occurs at ambient temperature, and the shift behavior of hysteresis loop associated with film thickness. With the film thickness increasing, the values of shift field and coercive field and other parameters such as remanence and shift ratio appeared complex variation. At a certain frequency, the large GMI effect is only observed in some films, which have good magnetic properties including low coercivity, low remanence ratio and high shift ratio. The results indicated that the thickness dependence of magnetic properties nonlinearly determined the GMI effect in Co 73 Si 12 B 15 thin films. [ABSTRACT FROM AUTHOR]

Reducing production cost and upgrading current capacity are the key issues for the commercialization of YB2 Cu3O7-δ (YBCO) high-temperature superconducting coated conductors. In this paper, a novel double-sided ion-beam-assisted deposited (IBAD) MgO template has been proposed and introduced for the deposition of YBCO coated conductors on both sides, which contributes significantly to the performance improvement and production cost cutting. In this template, chemical solution derived amorphous Y2 O3 layer was coated on untreated hastelloy tapes to obtain nanometer-level flatted surface with root-mean-square roughness values of 0.8 and 0.5 nm (5 μm × 5 μm area) for each side, respectively. Based on the smooth surface, double-sided IBAD-MgO and homoepitaxial MgO films were deposited on the Y 2O3 coatings by a two-step process. The biaxial textures of meter-long double-sided MgO tape showed ω-scans of (200) MgO and Φ-scans of (220) MgO yield full width at half maximum values of 2.5°–3° and 4.5°–6°for one side, respectively, as well as 2.6°–3.2° and 5.6°–6.5°for the other side. Finally, the double-sided YBCO films deposited on the LaMnO3 buffered MgO template achieved a high-transition temperature of 90 K and an overall critical current of 290 A/cm at self-field (110 and 180 A/cm for each side). [ABSTRACT FROM PUBLISHER]

We report the formation of amorphous Cu50Zr50 films with a large-area of more than 100 cm2. The films were fabricated by ion beam assisted deposition with a slow deposition rate at moderate temperature. The amorphous films have markedly enhanced thermal stability, excellent flexibility, and high reflectivity with atomic level smoothness. The multifunctional properties of the amorphous films are favorites in the promising applications of smart skin or wearable devices. The method of preparing highly stable amorphous metal films by tuning the deposition rate instead of deposition temperature could pave a way for exploring amorphous metal films with unique properties. [ABSTRACT FROM AUTHOR]

Titanium nitride ( TiN x ) is regarded as a kind of promising plasmonic material for its high performances. We studied the influence of nitrogen partial pressure p n and deposition temperature T d on the structural and plasmonic properties of the TiN x thin films prepared by ion beam assisted deposition (IBAD). The results show that IBAD is an effective method to tailor the plasmonic properties of TiN x films in visible and near-IR region. The plasmonic properties of the films have significant T d and p n dependence. Higher p n and lower T d can reduce the plasma frequency and the plasmon resonance. Higher p n and higher T d can reduce the optical loss of the samples. The modification of the plasmonic properties is related to the variation of nitrogen content. [ABSTRACT FROM AUTHOR]

Joint experimental and theoretical study of Ge nanoislands growth on groove-patterned Si(001) substrate prepared by ion-beam-assisted nanoimprint lithography is carried out. Prepatterning procedure includes ion irradiation of Si substrate through imprinted resist mask with linear mounds and subsequent multistep oxidation/ etching of irradiated Si domains. It is shown that the temperature of subsequent heteroepitaxy on the groovepatterned substrate affects the location of Ge nanoislands. The effect is attributed to additional surface tensile strain formed inside grooves by residual irradiationinduced defects. The interplay of strain and surface curvature makes the critical size of 3D nanoisland larger at the concave regions in grooves than between them. At lower temperatures this results in nanoisland nucleation at the top of mounds. At higher temperatures due to the intensive migration of Ge inside grooves the formation of large nanoislands in grooves occurs. The effect of temperature on the location and size of nanoislands is described by Monte Carlo simulations. [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]

A fabrication process has been developed for high energy ion beam assisted deposition (IBAD) biaxial texturing of ultrathin (~1 nm) MgO films, using a high ion-to-atom ratio and postdeposition annealing instead of a homoepitaxial MgO layer. These films serve as the seed layer for epitaxial growth of materials on amorphous substrates such as electron/X-ray transparent membranes or nanocalorimetry devices. Stress measurements and atomic force microscopy of the MgO films reveal decreased stress and surface roughness, while X-ray diffraction of epitaxial overlayers demonstrates the improved crystal quality of films grown epitaxially on IBAD MgO. The process simplifies the synthesis of IBAD MgO, fundamentally solves the "wrinkle" issue induced by the homoepitaxial layer on sub-50 nm membranes, and enables studies of epitaxial materials in electron/X-ray transmission and nanocalorimetry. [ABSTRACT FROM AUTHOR]

A bioactive two-layer coating consisting of hydroxyapatite (HA) and yttria-stabilized zirconia (YSZ) was investigated on cylindrical polyetheretherketone (PEEK) implants using ion beam assisted deposition (IBAD). Post-deposition heat treatments via variable frequency microwave annealing with and without subsequent autoclaving were used to crystallize the as-deposited amorphous HA layer. Microstructural analysis, performed by TEM and EDS, showed that these methods were capable of crystallizing HA coating on PEEK. The in vivo response to cylindrical PEEK samples with and without coating was studied by implanting uncoated PEEK and coated PEEK implants in the lateral femoral condyle of 18 rabbits. Animals were studied in two groups of 9 for observation at 6 or 18 weeks post surgery. Micro-CT analysis, histology, and mechanical pull-out tests were performed to determine the effect of the coating on osseointegration. The heat-treated HA/YSZ coatings showed improved implant fixation as well as higher bone regeneration and bone-implant contact area compared to uncoated PEEK. The study offers a novel method to coat PEEK implants with improved osseointegration. [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]

NiTi shape memory alloy (SMA) thin films were fabricated using biased target ion beam deposition (BTIBD), which is a new technique for fabricating submicrometer-thick SMA thin films, and the capacity to exhibit shape memory behavior was investigated. The thermally induced shape memory effect (SME) was studied using the wafer curvature method to report the stress-temperature response. The films exhibited the SME in a temperature range above room temperature and a narrow thermal hysteresis with respect to previous reports. To confirm the underlying phase transformation, in situ x-ray diffraction was carried out in the corresponding phase transformation temperature range. The B2 to R-phase martensitic transformation occurs, and the R-phase transformation is stable with respect to the expected conversion to the B190 martensite phase. The narrow hysteresis and stable R-phase are rationalized in terms of the unique properties of the BTIBD technique. [ABSTRACT FROM AUTHOR]

Thin Fe 57 films with the thickness of 120 nm have been prepared on glass substrates by using the ion-beam-assisted deposition technique. X-ray diffraction, electron microdiffraction and Mössbauer spectroscopy studies have shown that as-deposited films are in a stressful nanostructured state containing the nanoscaled inclusions of α-phase iron with the size of ∼10 nm. Room temperature in-plane and out-of-plane magnetization measurements confirmed the presence of the magnetic α-phase in the iron film and indicated the strong effect of residual stresses on magnetic properties of the film as well. Subsequent thermal annealing of iron films in vacuum at the temperature of 450 °C stimulates the growth of α-phase Fe crystallites with the size of up to 20 nm. However, electron microdiffraction and Mössbauer spectroscopic data have shown the partial oxidation and carbonization of the iron film during annealing. The stress disappeared after annealing of the film. The magnetic behaviour of the annealed samples was characterized by the magnetic hysteresis loop with the coercive field of ∼10 mT and the saturation magnetization decreased slightly in comparison with the α-phase Fe magnetization due to small oxidation of the film. [ABSTRACT FROM AUTHOR]

CeO 2 is a promising material for the utilization of solar light in photocatalytic reactions. However, the major obstacle for these studies is the lack of reliable methods to incorporate the desired elements such as nitrogen into the crystal lattice of CeO 2 . In the present study, a nitrogen-doped CeO 2 thin film was synthesized by IBAD technique. With this technique, the nitrogen was heavily and uniformly doped into the CeO 2 thin films. XPS analysis clearly demonstrates the greatest N concentration of 25 mol% can be doped in CeO 2 thin films which is much higher than that obtained via traditional methods. The high resolution N 1s spectrum shows that nitrogen dopants are uniformly doped into CeO 2 lattice by substituting O. The XRD results indicate ion bombardment on the growing film surface does not alter the crystal structure of the film by itself. Instead, the heavy nitrogen doping induces smaller grain size of CeO 2 . The SEM images show that with the increase of N doping, the surface become smoother with smaller particle size. The heavily nitrogen doping also induces a red shift of the visible light absorbance from 380 nm to 450 nm. [ABSTRACT FROM AUTHOR]

Fullerene C 70 thin films were deposited by resistive heating on glass substrates and the thickness were approximated to be 150 nm. The effect of energy deposition by 55 MeV Si ions on the optical and structural properties of the prepared thin film samples is investigated. The samples were irradiated with 55 MeV Si ions within fluence range from 1 × 10 12 to 3 × 10 13 ions/cm 2 . For optical studies, the pristine and the Si ion irradiated samples are examined by UV–visible absorption spectroscopy and Raman spectroscopy. UV–visible absorption studies reveal that the absorption peaks of irradiated samples decrease with a decrease in the band gap of the thin films. The damage cross-section ( σ ) and radius of damaged cylindrical zone ( r ) are determined as ∼0.6 × 10 −13 cm 2 and ∼1.41 nm, respectively from the Raman spectra. Raman studies also suggest that at higher fluence (up to 3 × 10 13 ions/cm 2 ), the damage caused by the SHI results in partial amorphization of fullerene C 70 thin film. Modification in the surface properties has been investigated by atomic force microscopy; it has revealed that the roughness decreases and average particle size increases with the increase in fluences. [ABSTRACT FROM AUTHOR]