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paper-like films of reduced graphene oxide with controllable shapes and thickness were prepared via funnel filtration and thermal reduction of graphene oxide (GO), which could work as flexible surface-enhanced Raman scattering (SERS) substrates to detect Rhodamine 6G (R6G) molecules. The SERS signal intensity of R6G on annealed films was found to be related with the annealling temperature. The most intense signal was observed for the film obtained at 800 °C. While for the sample annealed at 1000 °C, no SERS signal could be detected. The underlying mechanism for the difference was discussed. The reported preparation process of flexible rGO paper is simple and cost-effective, which shows great potential in rapid biochemical analysis of agricultural products with irregular surfaces. [ABSTRACT FROM AUTHOR]

This paper identifies and characterizes complex core-shell morphologies in thin films of a polybutadiene- block -poly(2-vinyl pyridine)- block -poly(tert -butyl methacrylate) (BVT) triblock terpolymer. The spin-coated BVT film develops into two distinct microphase separated structures with thickness variation during solvent annealing in a well-controlled atmosphere of THF vapor. Cylinders parallel to the film plane are found in thinner terraces and featureless areas that are characteristic of the lying lamella phase, or disordered structures are found in thicker terraces. Underneath the surface, we found that these microphase separated structures exhibit core-shell morphologies, i.e. surface ablation revealed core-shell cylinders and core-shell perforated lamellae under a cover layer in each terrace. Time-resolved study upon solvent annealing shows that the dynamics of microdomain evolution are affected by the extent of annealing time. The structural development in the BVT terpolymer films on corrugated supports demonstrates flow-field-induced sequenced ordering of the microdomains. • Block copolymer develops into two distinct morphologies • Complex core-shell morphologies are revealed beneath the surface [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Simulation of carbide layer growth during carburizing and annealing tantalum. • Effect of annealing on carburized tantalum. • Obtaining different surface microstructures: TaC, Ta 2 C or Ta(C) + Ta 2 C. Abstract This paper describes a model developed to simulate the evolution of carbide layers (TaC/Ta 2 C) formed during carburizing and annealing treatments of tantalum. The model is based on a parabolic evolution of the layer thickness during the growth, and on the carbon conservation during the annealing. In order to validate this model a MATLAB® program was developed. It enables the prediction of the evolution of the tantalum carbide layers (nature and thickness) for a desired treatment defined by a temperature, a carburizing and an annealing duration. [ABSTRACT FROM AUTHOR]

In this paper, a novel hierarchical SnO 2 assembled of nanotubes was successfully prepared using flower-like ZnO nanorods as self-etching template. Alkaline reaction environment led to the removal of the template without post-treatment. The as-prepared samples were characterized by X-ray powder diffraction (XRD), fourier transform infrared (FTIR), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscope (HRTEM), photoluminescence (PL), Brunauer–Emmett–Teller (BET) and Zeta potential analysis. The as-prepared hierarchical SnO 2 nanostructure showed uniform flower-like morphology, small grain size, and good crystallinity even without annealing. The product also had a very rough surface with a high specific area about 80 m 2  g −1 . The porous hierarchical SnO 2 demonstrated high degradation rate (∼94%) for methylene blue (MB) in 30 min under UV light. Furthermore, the photocatalytic performance was sustained over 3 cycles, indicating it may have potential applications in wastewater treatment. [ABSTRACT FROM AUTHOR]

Due to the limited heating power in non-oxidation furnace of continuous strip processing facilities of heating stage, selective oxidation with higher oxygen pressure is practically inevitable, which will greatly influence the quality of coating during immersion into the zinc bath. In this paper, the oxidation behaviors of DP980 advanced high strength steel are studied during annealing in a pure H 2 atmosphere with controlled water pressure ranging from 0.033 to 0.094 bar ( P H2O / P H2 ) and soaking time from 30 s to 2 h. The oxidation proceeds as a combination of external formation of Mn oxides and internal formation of Mn 2 SiO 4 , MnSiO 3 and SiO 2 from the subsurface of the steel into the matrix. As the water pressure increases from 0.033 to 0.094 bar, it can be seen that the amount of oxide particles and coverage on the surface of the steel seems to decrease initially and increase afterwards. The sequence of oxides determined by oxygen partial pressure was calculated and illustrated using thermodynamics with alloys activity. Oxide growth mechanism during annealing and the effect of water pressure on the amount of oxide particles were also discussed. [ABSTRACT FROM AUTHOR]

Low-temperature direct bonding is a promising method to integrate two or more dissimilar materials into one composite without large thermal stresses. In this paper, we describe a bonding process for silicon and quartz glass via vacuum ultraviolet/ozone (VUV/O 3 ) activation and a multistep, low-temperature annealing process. A strong bonding strength and a bonding interface without any microcracks were obtained after annealing at 200 °C. The surfaces and bonding interface were characterized. After the organic contaminants were removed by VUV/O 3 , the treated surfaces were very hydrophilic. In addition, the VUV/O 3 -induced surface oxidation increased, resulting in oxide asperities on the substrates. These newly generated surface asperities might possess a strong deformability based on the water stress corrosion effect, leading to gap closure after low-temperature annealing. Moreover, a model for the mechanism of the VUV/O 3 -activated bonding was proposed. [ABSTRACT FROM AUTHOR]

Bimetallic nanostructures (BMNSs) have gained significant attention because of their multi-functionality, site-specific response and electronic heterogeneity along with the additional opportunities to tune physical and optical properties. In this paper, the systematic evolution of Au x Pd 1−x BMNS is thoroughly investigated in terms of morphological and optical properties through the solid state dewetting on c -plane sapphire. The bilayer composition and deposition order change are coherently tested along with the conventional growth parameter control. By the systematic control of annealing temperature, annealing duration and deposition thickness, the formation of various BMNSs demonstrate sharp distinctions at different Au x Pd 1−x compositions (x = 0.25, 0.50 and 0.75). In specific, the high Au percentage in the Au x Pd 1−x bilayers shows an enhanced dewetting due to the higher diffusivity and lower surface energy of Au atoms as compared to the Pd. Furthermore, the deposition order also induces a significant alteration on the dewetting process. Upon annealing, the evolution of BMNSs relies on the combination of atomic diffusion, inter-diffusion, alloying, surface and interface energy minimization and Rayleigh-like instability. Furthermore, the analysis of reflectance spectra demonstrates the development of the quadrupolar and dipolar resonance peaks, absorption band and their shift, induced by the localized surface plasmon resonance (LSPR) of various Au x Pd 1−x BMNSs. Specifically, the quadrupolar resonance peak is consistent ∼380 nm whereas the dipolar resonance peak and absorption dip are readily blue-shifted and narrowed along with the evolution of isolated and uniform BMNSs. [ABSTRACT FROM AUTHOR]

This paper investigated the controllable growth of Ge nanocrystal (nc-Ge) in (Ge, Er) co-doped ZnO film, and the relationship between the size of nc-Ge and the enhancement of Er 3+ related 1.54 μm photoluminescence (PL). It was found that nc-Ge with size of ∼5 nm was formed by annealing treatment at 600 °C. The intensity of 1.54 μm was significantly enhanced due to the existence of nc-Ge and showed an obvious dependence on nanocrystal size. The size of nc-Ge increased with the increase of the annealing temperature, and the nanocrystal with size of ∼5 nm made the most obvious contribution to PL enhancement. Prolonging annealing time could improve the crystalline structure of ZnO matrix but had no effect on PL intensity. The experimental results showed that the PL enhancement was mainly achieved by transferring the energy to Er through the resonance absorption of nc-Ge. [ABSTRACT FROM AUTHOR]

Surface islands formed by grain-boundary diffusion has been studied in Ni/Cu nanolayers by in-situ low energy ion scattering spectroscopy, X-ray photoelectron spectroscopy, scanning probe microscopy and ex-situ depth profiling based on ion sputtering. In this paper a new experimental approach of measurement of grain-boundary diffusion coefficients is presented. Appearing time of copper atoms diffused through a few nanometer thick nickel layer has been detected by low energy ion scattering spectroscopy with high sensitivity. The grain-boundary diffusion coefficient can be directly calculated from this appearing time without using segregation factors in calculations. The temperature range of 423–463 K insures the pure C-type diffusion kinetic regime. The most important result is that surface coverage of Ni layer by Cu atoms reaches a maximum during annealing and stays constant if the annealing procedure is continued. Scanning probe microscopy measurements show a Volmer-Weber type layer growth of Cu layer on the Ni surface in the form of Cu atomic islands. Depth distribution of Cu in Ni layer has been determined by depth profile analysis. [ABSTRACT FROM AUTHOR]

This paper reports on the electrical behavior of self-assembled gold nanoparticle films before and after high-temperature annealing in ambient environment. These films are made by depositing gold nanoparticles from a colloidal solution on glass substrates using centrifuge deposition technique. The current-voltage (I–V) characteristics of these films exhibits ohmic and non-ohmic properties for un-annealed and annealed films respectively. As the annealing time duration increases, the onset of non-ohmic behavior occurs at higher voltages. To understand the underlying mechanisms for the observed electrical conduction behavior in these films and how electrical conduction is effected by film morphology and structural properties before and after annealing, systematic comparative studies based on scanning electron microscopy (SEM), UV–vis absorption spectroscopy and X-ray photoelectron spectroscopy (XPS) have been performed. The morphology of the films shows that the assembled gold nanoparticles are distributed on the substrate in a random way before annealing. After 2 h annealing gold nanoparticles exhibit a higher filling fraction when examined by SEM, which means that they coalesce, upon annealing, with respect to un-annealed films. The UV–vis absorption spectra of the films show that there is a red-shift and broadening in the absorption band for the annealed films. The observed phenomenon is related to the plasmon near-field coupling effect and suggests that the nanoparticle ensembles interspacing has decreased. The structural and crystallinity of the films exhibit amorphous structure before annealing and pure crystalline phases with a preferential growth direction along the (111) plane after annealing. The XPS analysis further suggests the existence of the stable thin oxide layer in the phase of A u 2 O 3 in the annealed films. The I–V characteristics have been described by Simmons’ model for tunnel transport through metal-insulator-metal (MIM) junctions. The Fowler-Nordheim (F-N) plots show the transition of the in-plane charge transport mechanism from direct tunneling to field emission in annealed films. Our results suggest that, the formation of a thin layer of A u 2 O 3 , the proximity of the nanoparticles as well as their higher filling fraction are important parameters related with the tunneling process enhancement. The observed non-ohmic conductivity property can make these self-assembled gold nanoparticle films very useful structures in different applications such as sensing, resistors and other nanoelectronic applications. [ABSTRACT FROM AUTHOR]

This paper deals with some physical investigations on molybdenum oxide thin films growing on glass substrates by the thermal evaporation method. These films have been subjected to an annealing process under vacuum, air and oxygen at various temperatures 673, 723 and 773 K. First, the physical properties of these layers were analyzed by means of X-ray diffraction, Raman spectroscopy, scanning electron microscopy (SEM) and optical measurements. These techniques have been used to investigate the oxygen index in MoO x properties during the heat treatment. Second, from the reflectance and transmittance optical measurements, it was found that the direct band gap energy value increased from 3.16 to 3.90 eV. Finally, the heat treatments reveal that the oxygen index varies in such molybdenum oxides showing noticeably sensitivity toward ethanol gas. [ABSTRACT FROM AUTHOR]

In this paper, we report a facile and controllable two-step approach to produce indium tin oxide electrodes modified by copper(II) oxide nanoparticles (CuO/ITO) through ion implantation and annealing methods. After annealing treatment, the surface morphology of the CuO/ITO substrate changed remarkably and exhibited highly electroactive sites and a high specific surface area. The effects of annealing treatment on the synthesis of CuO/ITO were discussed based on various instruments’ characterisations, and the possible mechanism by which CuO nanoparticles were generated was also proposed in this work. Cyclic voltammetric results indicated that CuO/ITO electrodes exhibited effective catalytic responses toward glucose in alkaline solution. Under optimal experimental conditions, the proposed CuO/ITO electrode showed sensitivity of 450.2 μA cm −2 mM −1 with a linear range of up to ∼4.4 mM and a detection limit of 0.7 μM (S/N = 3). Moreover, CuO/ITO exhibited good poison resistance, reproducibility, and stability properties. [ABSTRACT FROM AUTHOR]

The paper presents results on laser nanostructuring of Ag thin films. The thin films are deposited on glass substrates by pulsed laser deposition technology. The as fabricated films are then annealed by nanosecond laser pulses delivered by Nd:YAG laser system operated at λ = 355 nm. The film modification is studied as a function of the film thickness and the parameters of the laser irradiation as pulse number and laser fluence. In order to estimate the influence of the environment on the characteristics of the fabricated structures the Ag films are annealed in different surrounding media: water, air and vacuum. It is found that at certain conditions the laser treatment may lead to decomposition of the films into a monolayer of nanoparticles with narrow size distribution. The optical properties of the fabricated nanostructures are investigated on the basis of transmission spectra taken by optical spectrometer. In the measured spectra plasmon resonance band is observed as its shape and position vary depending on the processing conditions. The fabricated structures are covered with Rhodamine 6G and tested as active substrates for Surface Enhanced Raman Spectroscopy (SERS). [ABSTRACT FROM AUTHOR]

In this paper, hydrogenated nanocrystalline silicon (nc-Si:H) thin films were deposited on mono-crystalline silicon substrate by plasma enhanced chemical vapor deposition (PECVD) under different hydrogen flow rates followed by a thermal treatment in an infrared furnace at different temperature ranging from 300 to 900 °C. The investigated structural, morphological and optoelectronic properties of samples were found to be strongly dependent on the annealing temperature. Raman spectroscopy revealed that nc-Si:H films contain crystalline, amorphous and mixed structures as well. We find that post-deposition thermal treatment may lead to a tendency for structural improvement and a decrease of the disorder in the film network at moderate temperature under 500 °C. As for annealing at higher temperature up to 900 °C induces the recrystallization of the film which is correlated with the grain size and volume fraction in the layer. We demonstrate that high annealing temperature can lead to a decrease of silicon–hydrogen bonds corresponding to a reduction of the amorphous matrix in the layer promoting the formation of covalent Si–Si bonds. The effusion of the hydrogen from the grown film leads to increase its density and therefore induces a decrease in the thickness of the layer. For post-deposition thermal treatment in temperature range under 700 °C, the post-deposition anneal seems to be crucial for obtaining good passivation quality as expressed by a minority carrier lifetime of 17 μs, as it allows a significant reduction in defect states at the layer/substrate interface. While for a temperature higher than 900 °C, the lifetime reduction is obtained because of hydrogen effusion phenomenon, thus a tendency for crystallization in the grown film. [ABSTRACT FROM AUTHOR]

A demonstration on a new technique of growing ScN using electron beam (e-beam) evaporator, coupled with successive ammonia (NH 3 ) annealing treatment is presented in this paper. The annealing temperature was varied at 750, 800, 850, 900 and 980 °C in order to obtain the best ScN layer. It was found that as the annealing temperature increased, the surface morphology of the ScN layer changed and ScN grains formed abundantly on the surface. The best surface of ScN layer was found in the 900 °C annealed sample. However, the roughness of the ScN increased with temperature. The photoluminescence (PL) peak of the near-to-band-edge (NBE) of ScN was observable in all samples and its intensity was the highest in the 900 °C annealed sample. Note that when the annealing treatment was conducted at 980 °C, the GaN PL peak is observable. Raman peaks of TO(X) of ScN were much evident at the annealing temperature above 900 °C. The formation of Sc N bonds was confirmed by X-ray spectroscopy (XPS) measurement. In the end of this work, we propose that the formation of ScN using the above techniques was successful, with thermal annealing at the temperature of 900 °C. [ABSTRACT FROM AUTHOR]

Organometal halide perovskite materials are emerging as solar cell materials, but the understanding of its performance is not yet enough, especially in its ferroelectricity which is important for the separation of photo-generated carriers. In this paper, we report investigations on influences of annealing temperature on the ferroelectricity of solution-processed methylammonium lead triiodide (CH 3 NH 3 PbI 3 ) thin film. It is found that annealing temperature has significant effect on the crystallinity and the crystal size, which further affects the ferroelectricity and the luminescence property. It indicates that the crystallization degree of the thin film and the uniformity of crystal growth are gradually getting better, and the phase contrast of positive polarization areas and negative polarization areas are gradually strengthened. [ABSTRACT FROM AUTHOR]

Critical issues need to be overcome to produce high performance Schottky diodes on gallium nitride (GaN). To activate dopant, high temperature thermal treatments are required but damage GaN surface where hexagonal pits appear and prevent any device processing. In this paper, we investigated the efficiency of cap-layers on GaN during thermal treatments to avoid degradation. Aluminum nitride (AlN) and silicon oxide (SiO x ) were grown on GaN by direct current reactive magnetron sputtering and plasma-enhanced chemical vapor deposition, respectively. AlN growth parameters were studied to understand their effect on the grown layers and their protection efficiency. Focused ion beam was used to measure AlN layer thickness. Crystalline quality and exact composition were verified using X-ray diffraction and energy dispersive X-ray spectroscopy. Two types of rapid thermal annealing at high temperatures were investigated. Surface roughness and pits density were evaluated using atomic force microscopy and scanning electron microscopy. Cap-layers wet etching was processed in H 3 PO 4 at 120 °C for AlN and in HF (10%) for SiO x . This work reveals effective protection of GaN during thermal treatments at temperatures as high as 1150 °C. Low surface roughness was obtained. Furthermore, no hexagonal pit was observed on the surface. [ABSTRACT FROM AUTHOR]

The coarsening of nanoporous gold (NPG) is significantly influenced by surface adsorbates at elevated temperature. In this paper, the effect of annealing atmosphere on the thermal growth of the porous structure was investigated by scanning electron microscopy and X-ray photoelectron spectroscopy. The NPG films were annealed in oxidative (air), inert (Ar) and reductive (CO) atmospheres at 100–600 °C for 2 h, respectively. The experimental results indicate that the NPG films show the best stability in the reductive atmosphere and the worst thermal properties in oxidative air. The NPG films annealed in air exhibit a significant pore growth at 200 °C and lose the porous structure at 300 °C, while those annealed in CO gas at 600 °C still remain the porous network. The thermal-induced coarsening of NPG films in air can be attributed to the desorption of O 2 from the NPG surface above 200 °C. In contrast, the stabilization of the NPG films in CO gas originates from the strong binding of CO with Au atoms to form a complex adsorption layer, which effectively inhibits the surface diffusion of Au atoms. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, the effect of thermal annealing and the duration of ion-exchange on the wetting parameters of the Ag+/Na+ ion-exchanged glasses have been reported. The analysis of wetting angle in different post-annealing temperatures shows that the wetting angle is increased by increasing the annealing temperature. The wetting parameters of Ag+/Na+ ion-exchanged glasses at different ion-exchanged periods of time have been also investigated. Scanning electron microscopy (SEM), UV–Visible spectroscopy and Fourier transform infrared (FTIR) spectroscopy have been used for determination of surface morphology and composition analysis of the prepared samples. The results of SEM show changes in the surface of the samples for different post-annealing temperatures. The optical characterization using UV–Vis spectroscopy shows an increase in the intensity of the absorption peak with increasing the ion-exchange duration. The FTIR spectroscopy confirms the formation of silver oxide material on the surface of Ag+/Na+ ion-exchanged glasses. [Copyright &y& Elsevier]

Abstract: This paper described the synthesis of vanadium dioxide (VO2) thin films on mica substrates with different annealing temperatures by an organic sol–gel method. We performed X-ray diffraction, scanning electron microscope and optical transmission measurements to investigate the effect of the annealing temperature on the crystalline structure, morphology, and phase transition properties of these films. The results showed that a polycrystalline structure with high crystallinity and compact surface at the annealing temperature of 500°C. The film exhibited a V6O13 phase and a flat surface with small grain size at 440°C. By contrast, the V n O2n−1 appeared when the annealing temperature at 540°C, and the film surface split into segregation of spherical grain and aggregates of continuously dendritic particles. Accordingly, the optimal annealing temperature was 500°C using the organic sol–gel method. And it turned out that the films mainly contained VO2 (M) phase at room temperature with high content of V4+ valence. Particularly, the films showed different changes in the infrared transmittance and hysteresis width during the phase transition. The largest transformation of the infrared transmittance before and after MIT was 73%, while the narrowest temperature hysteresis width was 8°C at 500°C. [Copyright &y& Elsevier]

Abstract: In this paper we present a laser-based method for metal nanostructures formation on flexible substrates. The analysis of the obtained structures is focused on their optical properties. The nanostructures are fabricated by laser processing of gold thin films. The films are deposited on PMMA and PVC substrates by classical PLD technology. The produced films are then annealed by nanosecond pulses delivered by Nd:YAG laser system operated at λ =355nm. At certain conditions the laser treatment leads to formation of discrete nanostructure on the substrate surface. The optical properties of samples fabricated at different conditions are examined by optical spectroscopy. Bending of the substrates at different angles is used to modify the characteristics of the produced structure which leads to change of its optical properties. In this way the plasmon band of the obtained nanostructures can be efficiently tuned in a range of about 30nm. The experiments of using produced structures in Surface Enhanced Raman Spectroscopy show that they can be an efficient alternative of the already developed. [Copyright &y& Elsevier]

Abstract: Zinc oxide (ZnO) films have the potential in the emerging thin-film technologies which can be employed in thin-film solar cells, transistors, sensors and other optoelectronic devices. In this work, low cost sol–gel spin-coating technique was used to synthesize the ZnO films. The influences of annealing temperature on the structural and optical properties of ZnO and aluminum doped ZnO (AZO) films were investigated. The structural properties of the ZnO films such as surface morphology and crystallinity were determined using atomic force microscopy (AFM) and X-ray diffractometry (XRD), respectively. The optical properties of the ZnO films were characterized by the ultraviolet–visible (UV–vis) spectroscopy and Tauc method was adopted to estimate the optical gap. The experimental results reveal that the thermal annealing treatment affects the properties of the ZnO films. The effects of the low range annealing temperature on the sol–gel ZnO films addressed in this investigation will be discussed in this paper. [Copyright &y& Elsevier]

Abstract: The present paper is devoted to studies of the composition and surface structure, including those after annealing at high temperatures, and catalytic activity in the reaction of naphthalene destruction of Ce-, Zr- and Mn-containing oxide layers on titanium obtained by means of the plasma electrolytic oxidation (PEO) method. The composition and structure of the obtained systems were investigated using the methods of X-ray phase and energy dispersive analysis and scanning electron microscopy (SEM). It was demonstrated that Ce- and Zr- containing structures had relatively high thermal stability: their element and phase compositions and surface structure underwent virtually no changes after annealing in the temperature range 600–800°C. Annealing of Ce- and Zr-containing coatings in the temperature range 850–900°C resulted in substantial changes of their surface composition and structure: a relatively homogeneous and porous surface becomes coated by large pole-like crystals. The catalytic studies showed rather high activity of Ce- and Zr-containing coatings in the reaction of naphthalene destruction at temperatures up to 850°C. Mn-containing structures of the type MnO x +SiO2 +TiO2/Ti have a well-developed surface coated by “nano-whiskers”. The phase composition and surface structure of manganese-containing layers changes dramatically in the course of thermal treatment. After annealing above 600°C nano-whiskers vanish with formation of molten structures on the surface. The Mn-containing oxide systems demonstrated lower conversion degrees than the Ce- and Zr-containing coatings, which can be attributed to substantial surface modification and formation of molten manganese silicates at high temperatures. [Copyright &y& Elsevier]

Abstract: In the present paper, the effects of electric field annealing on interface diffusion of Cu/Ta/Si stacks were studied by means of XRD, XPS and TEM. The barrier property of Ta films was evaluated based on the diffusion of Cu atoms. It was found that the external electric field accelerates the diffusion of Cu atoms through Cu/Ta/Si interfaces during annealing. With the increment of annealing temperature, the effect of the electric field upon the atomic diffusion becomes more significant. The mechanism of accelerated interface diffusion is suggested and the failure of Ta barrier layer is discussed based on the mobility of vacancies and Cu atoms inside Cu/Ta/Si stacks caused by the electric field. [Copyright &y& Elsevier]

Abstract: The paper presents the results of theoretical and experimental researches of the analysis of nanopowder ZnO and ZnO-based structures formation mechanisms by means of pulse laser reactive technology (λ =1.06μm, τ =10−7 to 10−5 s). The developed 2D model combines non-stationary heat transfer and fluid motion along with the calculated profile of surface deformation. The characteristics of the dispersive and chemical compositions and structural parameters of the synthesized nanopowder together with the influence of the energy of laser impulse evaporation, its duration and gas pressure in the reaction chamber have been studied using X-ray diffractrometry (XRD), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM). Particle size distribution analysis of ZnO has shown that the majority of them range from 5 to 60nm in size. The photoluminescence emission spectra of the initial ZnO nanopowder at room temperature have been identified. [Copyright &y& Elsevier]

Abstract: This paper describes experimental relationship between surface acoustic wave (SAW) properties of two-port SAW resonators based on polycrystalline aluminum nitride (AlN) thin films grown on Si substrates by using a pulsed reactive magnetron sputtering system and their geometry''s parameters. Moreover, the influence of post-deposition heat treatment on SAW properties of AlN thin films was investigated at different annealing temperature (600°C and 900°C). The measurement results show the number of the inter-digital transducers (IDT) finger pairs (N), the number of reflectors grating pairs (R) and the IDT center-to-center distance (L) related to insertion loss of SAW resonators. The best result of insertion loss was 15.6dB for SAW resonators with R =160 pair, N =5 pair and L =750μm. At the same geometry parameters, the SAW velocity and insertion loss were improved slightly after annealing at 600°C and were worse for the films annealed at 900°C by changes in the surface morphology and stress on the film. [Copyright &y& Elsevier]

Abstract: In this paper, MgO film is successfully grown on polycrystalline and monocrystalline alumina substrates using sol–gel method, and polycrystalline and monocrystalline Mg–Al spinels are fabricated by solid state reaction, respectively. The influence of annealing temperature and time on the lattice structure and growth of the formed Mg–Al spinel layer has been investigated. It is indicated that the annealing temperature and time on the as-synthesized polycrystalline Mg–Al spinel has more significant influence than that of single crystal Mg–Al spinel. The thickness of the Mg–Al spinel layer increases with the annealing temperature, both for polycrystalline and for monocrystalline alumina substrates. And the significantly intercrystalline diffusion of Mg2+ ions and Al3+ ions results in a quicker growth velocity of the Mg–Al spinel layer than that of intracrystalline diffusion. [Copyright &y& Elsevier]

Abstract: The paper reports on thermal stability of alumina thin films containing γ-Al2O3 phase and its conversion to a thermodynamically stable α-Al2O3 phase during a post-deposition equilibrium thermal annealing. The films were prepared by reactive magnetron sputtering and subsequently post-deposition annealing was carried out in air at temperatures ranging from 700°C to 1150°C and annealing times up to 5h using a thermogravimetric system. The evolution of the structure was investigated by means of X-ray diffraction after cooling down of the films. It was found that (1) the nanocrystalline γ-Al2O3 phase in the films is thermally stable up to 1000°C even after 5h of annealing, (2) the nanocrystalline θ-Al2O3 phase was observed in a narrow time and temperature region at ≥1050°C, and (3) annealing at 1100°C for 2h resulted in a dominance of the α-Al2O3 phase only in the films with a sufficient thickness. [Copyright &y& Elsevier]

Abstract: In this paper, we describe the physical properties and electrical characteristics of thin Sm2O3 dielectric films deposited on Si (100) by means of rf reactive sputtering. The structural and morphological features of these films were studied, as a function of the growth conditions (three various argon-to-oxygen flow ratios: 10/15, 15/10 and 20/5, and temperature from 600 to 800°C), by x-ray diffraction, atomic force microscopy, and x-ray photoelectron spectroscopy. It is found that Sm2O3 dielectric prepared under 15/10 flow ratio and annealed at 700°C exhibits a thinner capacitance equivalent thickness and excellent electrical properties, including the interface trap density, the hysteresis and frequency dispersion in the capacitance–voltage curves. This condition is attributed to the reduction of the interfacial SiO2 and silicate formation, and the small of surface roughness due to the optimization of oxygen in the Sm2O3 film. [Copyright &y& Elsevier]

Abstract: Registration markers are crucial in connecting scanning tunneling microscope (STM) lithographed nano- and atomic-scale devices to the outside world. In this paper we revisit an ultra high vacuum annealing method with a low thermal budget that is fully compatible with etched registration markers and results in clean 2×1 reconstructed Si(100) surfaces required for STM lithography. Surface contamination is prevented by chemically stripping and reforming a protective silicon oxide layer before transferring the sample to the vacuum system. This allows for annealing temperatures of only 900°C, where normally carbon contaminants result in the formation of SiC clusters on the surface at annealing temperatures below 950°C. Reactive ion etched marker structures with an etch depth of 60nm and a typical lateral dimension of only 150nm survive a 900°C flash anneal. [Copyright &y& Elsevier]

Abstract: As a traditional etchant, pure buffered hydrofluoric acid (BHF), does not possess the ability to etch BST thin films annealed at high temperature, even though it works greatly on as-deposited Ba0.5Sr0.5TiO3 (BST) films. In this paper, we developed an etchant by mixing BHF and strong acid (HNO3, HCl, H2SO4 and H3PO4) and use it successfully on BST films annealed with high temperature. The experimental results show that a 1–8wt% of strong acid acts as an efficient catalyst and the etching speed is significantly improved. The etched BST films show little distortions and smooth etching edges were recorded. [Copyright &y& Elsevier]

Abstract: This paper, being a complementary one to our earlier report (Chem. Phys. Lett. 387 (2004) 110), presents a detailed description of the surface cleaning method applied for molecular beam epitaxy (MBE)-grown zinc-blende (zb)-MnTe epilayers. In particular, surface compositional changes induced by multistep Ar+ ion sputtering (with beam energy, E i, fixed between 0.5 and 2.0keV) and subsequent annealing of zb-MnTe crystal have been studied by using X-ray photoelectron spectroscopy (XPS). It was found that Ar+ ion bombardment with E i =1.5keV appeared as the crucial preparation step (either in multistep- or in post-anneal sputtering), which provided an efficient removal of the surface oxides and contaminants and led to nearly stoichiometric surface composition, namely [Te]/[Mn]=0.97. Detailed analysis of the Mn 2p core-level spectrum (acquired in Mg Kα mode) for clean zb-MnTe surface exhibited good consistency with the results of the relevant analysis reported earlier (see the reference above). [Copyright &y& Elsevier]

Abstract: This paper describes the formation of nanocrystalline tungsten oxide thin films by two-step thermal annealing of vacuum evaporated tungsten oxide films. The films were annealed at different temperatures to form semiconducting WO3 films suitable for gas sensor and other electronic device applications. It was found that the film annealed at 300°C have a uniform nanocrystalline structure compared with high temperature annealed films. When these nanocrystalline films were re-annealed in higher temperature region (>500°C), no any variation of surface morphology and crystalline structure was observed. These experimental results indicated that stable nanocrystalline WO3 films could be prepared by two-step annealing. [Copyright &y& Elsevier]

• Experimental-theoretical study: XPS, gaseous probe adsorption, DFT calculations. • The periodicity of the potential energy is not broken by the stacking fault. • Stacking faults do not impact the surface electronic structure. • Surface reactivity is governed by the morphology and the manganese environments. This paper investigates the role of the stacking fault (5%, 20% and 50%) and the morphology of Li 2 MnO 3 lamellar materials, issued from coprecipitation method with three annealing temperatures, on the surface reactivity. The structure and the morphology have been characterized by XRD, SEM and TEM. We studied the surface reactivity of these materials by combining X-ray photoemission spectroscopy (XPS), gaseous adsorption and first-principle calculations. An evolution of the reactivity toward the SO 2 acid gaseous probe has been observed for the three materials, from pure redox mechanism toward mixed acid-base/redox mechanisms, respectively for 5% and 50% of stacking faults. We demonstrated that the electronic structure of Li 2 MnO 3 being not modified by stacking faulted. Thus, the surface reactivity of faulted Li 2 MnO 3 is not linked to the SF rate but only governed by the accessible crystalline surfaces and the manganese environments at the surface atomic layer. The formation of (0 0 1)-Li surface according to the Li-overstoichiometry on the extreme surface and the random particles shape of the more faulted materials are responsible of the reactivity tuning. [ABSTRACT FROM AUTHOR]

• ZrO 2 films was fabricated by electrohydrodynamic atomization coupled with laser annealing. • The interaction of laser irradiation with ZrO 2 films was investigated. • Tribological and corrosion properties of films was improved after laser irradiation. This paper aims to provide a simple and rapid fabricating method for solution-based ZrO 2 thin films. The ZrO 2 thin film was firstly deposited on a 316L stainless steel substrate by electrohydrodynamic atomization. Then the crystallization process was carried out by a 4W Nd:YAG laser with a wavelength of 1064 nm. The morphology, structure and evolution of chemical bonds (Zr and O) were evaluated by transmission electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy. After laser annealing, the O 1s (O-containing ions in ZrO 2) fraction rose from 22.6% to 51.1%, and the principal tetragonal phase composition was obtained. The large temperature gradients that derived from the photothermal effect contribute to the fast crystallization during the laser treatments. The tribological and electrochemical corrosion experiments reveal that the laser crystallized films have significantly well wear and corrosion resistance, close to those of conventionally crystallized films. This fabricating method is simple, energy-saving and could achieve the spatially-resolved crystallization of films with a minimal temperature increase on the underlying substrates. [ABSTRACT FROM AUTHOR]

• Thermal-spraying was used to deposit the coating on a bronze substrate. • Concentrated solar energy was used for annealing of a Ni-Al coating. • The solar-annealed coatings present high hardness, wear and corrosion resistance. • Concentrated solar heat treatment is superior to other conventional methods. An improvement in the hardness, wear and corrosion resistance of a thermal-sprayed nickel-aluminium coating has been described in this paper, by using a post-deposition annealing treatment in a vertical concentrated solar radiation furnace at Plataforma Solar de Almeria, Spain. Annealing temperatures between 900 and 970 °C were used. It has been determined that the heat treatment leads to a 56% increase in hardness, 65% increase in scratch resistance and coating adhesion to the substrate, coupled with a 20% improvement in wear resistance, compared to the non-annealed reference. The improvement in mechanical properties has been related to increased heating gradient, formation of intermetallic Ni x Al compounds in the structure of coatings, as well as to a better compacting of coated assembly. The solar annealing treatment leads also to an improvement in the properties of coatings, with up to 87% in terms of corrosion resistance, and 20% in terms of wear resistance, comparing to the reference. [ABSTRACT FROM AUTHOR]

Rational construction of three-dimensional (3D) porous carbon nanotubes (CNTs) hierarchical architectures can provide diverse frameworks for fabrication of functionalized electrodes to effectively enhance their electrochemical performance. In this paper, a modified electroless deposition (ELD) process for uniformly anchoring of Ni@Pd seeds on substrates is reported. The tightly immobilized bi-metal seeds without aggregation during annealing leads to in-situ growth of uniform intertwined CNTs arrays. The ELD seeding and CNTs growth method was successfully applied on different 3D carbon- and metal- based substrates. The 3D interconnected CNTs/carbon composites offer a hierarchical micro-/nano- network to facilitate electrolyte infiltration, while the CNTs arrays can effectively improve the electrical conductivity and enlarge the active surface area of the hybrids substrate. The hierarchical hybrid electrodes exhibit enhanced electrochemical performance in electrocatalysis and as a supercapacitor. The ELD process can be a general and scalable strategy for industrialized fabrication of any 3D carbon-based substrate and will be much promising in the applications of energy storage and conversion. Unlabelled Image • Modified electroless deposition process is fabricated to uniformly anchoring the Ni@Pd seeds on substrates. • The tightly immobilized bi-metal seeds without aggregation lead to in-situ growth of uniform intertwined CNTs arrays. • The ELD seeding and CNTs growth method can be applied on different 3D carbon- and metal- based substrates. • The electrical conductivity and the active surface area of the CNTs/carbon cloth hybrid substrate can be highly improved. [ABSTRACT FROM AUTHOR]

A photoelectrochemical (PEC) cell made of metal-free carbon nitride (g-C 3 N 4 ) @siliconnanowire(Si NW) arrays (denoted as Si NWs/g-C 3 N 4 ) is presented in this work. The as-prepared photoelectrodes with different mass contents of g-C 3 N 4 have been synthesized via a metal-catalyzed electroless etching (MCEE), liquid atomic layer deposition (LALD) and annealing methods. The amount of g-C 3 N 4 on the Si NW arrays can be controlled by tuning the concentration of the cyanamide solution used in the LALD procedure. The dense and vertically aligned Si NWs/g-C 3 N 4 core/shell nanostructures were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD). In comparison with FTO/g-C 3 N 4 and Si NW samples, the Si NWs/g-C 3 N 4 samples showed significantly enhanced photocurrents over the entire potential sweep range. Electrochemical impedance spectroscopy (EIS) was conducted to investigate the properties of the charge transfer process, and the results indicated that the enhanced PEC performance may be due to the increased photo-generated interfacial charge transfer between the Si NWs and g-C 3 N 4 . The photocurrent density reached 45 μA/cm 2 under 100 mW/cm 2 (AM 1.5 G) illumination at 0 V (vs. Pt) in neutral Na 2 SO 4 solution (pH ∼ 7.62). Finally, a systematical PEC mechanism of the Si NWs/g-C 3 N 4 was proposed. [ABSTRACT FROM AUTHOR]