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ReS2 is an emerging member from the family of layered transition metal dichalcogenides (TMDCs) and has interesting optical and electrical properties due to its weak interlayer coupling. Systematically, layered ReS2 structures were successfully synthesized by hydrogen assisted controlled chemical vapor deposition method. DFT calculations were performed to determine the interface energies between ReS2 layer and SiO2/Si, sapphire and mica substrates. Calculated interface energy and % strain are lower for mica as compared to SiO2/Si and sapphire, which helps to grow smooth layers on mica substrate as compared to SiO2/Si. At atmospheric pressure, larger interface strains are produced between substrate and growing layers which transforms the 2D layered structure to 3D flower-like structures. Under the controlled conditions, substrates surface energy is playing a key role and mica with the freshly clean surface is probably facilitating the atoms to grow along in-plane direction to form smooth films. Finally, photo-detector measurements were made under the extreme conditions (high energy and intense light with large voltage sweep) to check the stability and reliability of the devices. The good stability, sensitivity (217 mAW−1) and fast response (Trise = 0.61 s, Tdecay = 1.59 s) of the devices reflects the quality of the synthesize product for their use in the future optoelectronic devices.

We present optically modified Sb2O3 thin film as a multi-functional layer that can be used as UV blocking, Near Infrared (NIR) transmitting and anti-reflecting layer suited for solar energy harvesting. Optical modifications are achieved by transition metal (Mn, Ni and Cu) doping through vacuum evaporation and solid state grinding which introduces new sidewise outgrowths emerging on the previously reported thorn structure of the film. The new structures are found growing along [110] direction, reducing the growth of thorns along [111] direction. Though the UV absorbance and wavelength range of absorbance are larger for transition metal doped Sb2O3 thin films, their UV reflectance is very low compared to the undoped films. However, they all show very good absorption in UVB and UVC regions and partial absorption in UVA region like undoped Sb2O3 thin films. Ultraviolet Protection Factor of all the films lie in the range 25–50 showing their competent UV blocking ability. NIR transmittances of Sb2O3 thin film increases with Ni and Mn doping, making them appropriate for NIR transmitting layers in cover glass of IR sensors and solar thermal energy collectors. Considering the multi-functionality, the overall performance of transition metal doped Sb2O3 thin films are more efficient than undoped film.

Wear-resistant performance is a critical property of the surface coated functional fabric during the cyclical abrasion of wearing procedure. However, inorganic nano-materials cannot easily graft onto the hydrophobic fabric substrate with weak interface interaction resulting in the unsatisfactory washing and wearing performance. Herein, the wear-resistant conductive polyester fabric with polyurethane - silver - polyurethane (PU-Ag-PU) sandwich micro-structure decoration was successfully fabricated via a facile spray coating route of water soluble polyurethane (WPU) and the in-situ synthesis of silver nanoparticles (AgNPs). The obtained fabric exhibits excellent conductivity with surface resistance of 4.95 Ω/sq. which is far below than the case without sandwich micro-structure (1.32 × 104 Ω/sq) because of the rearrangement and quantum tunneling effect of AgNPs in the nanocomposite coating layer. More importantly, the wear resistance of the modified fabric has been greatly enhanced owing to the two-phase structure of polyurethane and sandwich micro-structure of coating. The weight loss of the sandwich micro-structure coated fabric is only 1.28% while it is 5.58% of the case without PU outer coating layer. Meanwhile, surface resistance of the sandwich fabric is merely increased an order of magnitude even after 1500 times of abrasion cycle test, showing a qualitative enhancement compared with that of the common structure (increased seven orders of magnitude). In short, the designed sandwich micro-structure significantly enhanced the electrical conductivity and wear-resistance of silver decorated fabric. The strategy of sandwich micro-structure design in this paper has indicated a potential way for the durable wear-resistant functional fabrics.

The purification of laser keyhole and improving molten pool flow are important means to restrain the porosity of laser-MIG hybrid welding of aluminum alloy. In this paper, four kinds of kerf were prefabricated by four common gases (Argon, Nitrogen, Air, Oxygen), which are used for studying the effect of kerf remelted layer on weld porosity. The experimental results show that the porosity is affected by the composition and thickness of the remelted layer. The porosity of Argon-weld and Nitrogen-weld is low, and that of Air-weld and Oxygen-weld is high. It increased linearly with the thickness of remelted layer (d). Regardless of the types of kerf, when the d is less than 136 μm, the porosity is less than 2%. When the d is thin, the purification of laser keyhole avoids the adverse effect of remelted layer oxide on the molten pool and reduces the porosity. When the d is thick, the influence of oxygen on surface tension and molten pool flow driven by it starts to dominate. It makes the temperature coefficient of surface tension change from negative to positive, and the molten pool change from ‘outward flow’ to ‘inward flow’, which prevent bubbles from escaping and increasing the porosity.

In this paper we report the semi-conductor of zinc oxide (ZnO) thin film deposited by reactive high power impulse magnetron sputtering (R-HiPIMS) on glass substrates without external heating. We focus on the influence of deposition parameter, the ratio of O2/Ar exactly, on the crystalline and electrical properties of ZnO films. It is found that n-type ZnO film with a high carrier concentration can be grown through HiPIMS technique, the ratio of O2/Ar remarkably affects the ZnO crystalline and electrical properties. At O2/Ar = 14/80 sccm, the ZnO film was orientated at c-axis (002) plane. Based on the temporal resolution optical emission spectroscopy (OES), for the proposal of the correlation of film structure with plasma radicals and the reaction process in ZnO growth, the components in plasma are diagnosed. It is concluded that in a higher oxygen partial pressure, owing to the high ionization rate in HiPIMS, the oxide layer formed between pulses is removed, the growth of a new oxide layer during the pulse is hindered, hence the growth rate is increased, and the carrier concentration caused from point defects in ZnO film is high.

In the present paper, we have prepared a multi-layer grating on a layer of gold film. The gratings laser damage threshold and damage morphologies have been tested using an 800 nm wavelength, 450 ps laser pulse. The gratings laser damage threshold is 0.95 J/cm2. Based on the tested damage characteristics and the calculated temperature field and stress field in gratings, the gratings damage mechanism has been analyzed. In theoretical calculation, the ionization process of dielectric layers in gratings and the distribution as well as evolution of the dielectric absorption coefficient have been considered. It can be concluded that the gratings damage process is thermal ablation action dominated.

SiO2 thin films were successfully deposited by plasma-enhanced atomic layer deposition (PEALD) using a divalent Si precursor (N,N′-tert-butyl-1,1-dimethylethylenediamine silylene) and oxygen plasma as reactants. The growth behavior of SiOx exhibited the typical self-limiting surface reaction depending on the precursor dose and plasma time over a wide deposition temperature range (80–200 °C) of the ALD window, showing a growth rate of about 1 A/cycle. The properties of the SiOx thin films were investigated using various analysis tools. The films exhibited a refractive index value of about 1.45–1.5, which corresponds to the refractive index of SiO2. The dielectric property was evaluated, and a high breakdown voltage and low leakage current was observed owing to the absence of carbon or nitrogen impurities. The density functional theory (DFT) was used to determine the growth mechanism during the ALD growth sequence.

High-performance fabrics with excellent electrical conductivity are increasingly attractive in modern industries. In this study, we report an electrically conductive silver/polyimide fabric (Ag/PIF) composite fabricated by combining an O 2 plasma pretreatment and a spray-assisted electroless plating (SAELP) technique. O 2 plasma treatment is firstly employed to roughen the surface of PIF and introduce functional aldehyde or ketone groups, which can act as a reducing agent and facilitate an even nucleation initiation of silver nanoparticles (Ag NPs) on the surface of the PIF. A silver ion solution and a reducing agent are then mixed evenly and sprayed to the PIF immediately to obtain Ag/PIF composites. The effects of O 2 plasma treatment and SAELP duration on the Ag/PIF composites are investigated and discussed. The results demonstrate that the silver layer is coated on the PIF uniformly and densely with a surface resistance of 0.1 Ω/sq. The first decomposition temperature of the Ag/PIF composites is up to 600 °C, indicating excellent thermal stability. The enhanced adhesion between Ag NPs and PIF endows the composites excellent fastness and superior flexibility. This work gives a new strategy for fabricating flexible, electrically conductive functional metal coated fabrics with high-performance properties in an efficient, facile and scalable way.

In this work, we describe the efficiency of ultra-violet (UV) photodetector performance through RF magnetron sputtered TiO2/WO3 bi-layer thin films. The structural, chemical, morphological and photocurrent response properties of as-grown TiO2, WO3 and bi-layer TiO2/WO3 films were systematically studied. Herein, the merit of enhanced oxygen vacancies in the TiO2/WO3 bi-layer plays a crucial role in photoresponse which is due to the shift of W4f spectrum towards lower binding energy side. Consequently, the addition of WO3 layer on TiO2 might be responsible for the superior charge carrier generation when light is illuminated on bi-layer thin film. Besides, linear I-V characteristics of as-resulted samples confirm the ohmic-contact behaviour between the photodetector material and the electrode. The bi-layer of TiO2/WO3 sample generates more electrons and these are might be trapped at Fermi-level of the film surface and it causes for the suppression of the charge carriers recombination rate. As a result, by fine tuning of the bi-layer of TiO2/WO3 structure provides a promising UV photodetector performance than the single-layer of TiO2 and WO3.

Flexible and porous poly (vinylidene fluoride)-titanium dioxide (PVDF-TiO2) hybrid prepared by sequential electrospinning and electrospraying was investigated for piezoelectric-driven semiconductor photocatalysis (PDSP) application. FT-IR and XRD results confirmed the direct preparation of nanofibrous PVDF layer with piezo-responsive β- and γ-crystalline phases by electrospinning. FE-SEM and FTIR spectra discerned that the fibrous structure of PVDF support and its piezo crystalline forms were preserved even after the process of TiO2 NPs deposition. In complementary to the visual observation by FE-SEM, XPS, and EDS, spectroscopical results confirmed the deposition of TiO2 NPs on the piezo responsive PVDF support. XPS studies confirmed that 53% of the hybrid surface was covered by TiO2 NPs. Under UV irradiated conditions, water bubble induced piezo activity enhanced the degradation of methylene blue (MB) by 99%. The PDSP efficacy of the hybrid was proportional to the extent of air bubble supply. The % of total organic carbon removal was 66, which indicate the mineralization of MB. The non-selective OH mediated photooxidation by this hybrid was found to be also suitable for degrading non-dye pollutants such as 4-aminophenol. Overall, PVDF-TiO2hybrid was found to be a potential PDSP useful for water remediation and detoxification.

The effective synthesis of two-dimensional (2D) heterostructures is essential for their use in electronic devices. In this study, by using atomic layer deposition (ALD), 2D transition metal dichalcogenide (TMD) heterostructures were grown by a halide precursor. This study shows the growth characteristics of the fluoride precursor compared to the chloride precursor used for the synthesis of the TMD on the graphene layer and the other TMD layer. Additionally, a carbonyl precursor was used for comparison with the halide precursor in terms of the thermal stability. From these experiments, the fluoride precursor was adequate for synthesizing on the graphene, however, was inappropriate for the TMD/TMD heterostructure because of its etching characteristic. Meanwhile, the chloride precursor was appropriate for the TMD/TMD heterostructure, even for a low binding energy with the substrate, but was inadequate in forming the TMD/graphene heterostructure, even if the ALD cycle increased. Through our experiments, we show, for the first time, that there exists a suitable halide precursor for a 2D layer for a substrate.

The present study aims to demonstrate that operating the HiPIMS discharge in bipolar regime (BP-HiPIMS) enables an energy-enhanced deposition process of high-quality hydrogen-free DLC thin films (high hardness, low coefficient of friction, good wear resistance, good adherence to the substrate and very low surface roughness). The structural and mechanical properties of DLC thin films deposited using the BP-HiPIMS technique were compared to those of the films prepared using a conventional HiPIMS process, under various deposition conditions. The BP-HiPIMS technique generates an energetic ion population and a substantial increase in the ion flux as compared to the conventional (monopolar) HiPIMS. This phenomenon overcomes the limitations when working with insulating or high electrical resistivity materials (both substrates and coatings), i.e. the need to accelerate the film-forming species. Energetic enhanced deposition conditions during bipolar HiPIMS facilitate the densification (up to 2.7 g/cm3) of amorphous carbon thin films which results in an increase in the film hardness (23 GPa) when depositing on Si substrates, without using substrate bias voltage, adhesion interfacial layer or substrate pre-treatment. Besides high hardness, the BP-HiPIMS process allows growing DLC coatings with good elastic strain to failure and high resistance to plastic deformation and cracking.

Surface laser treatments are often used on metals and metal alloys to improve the material's hardness and corrosion resistance. Investigating the reasons for this property enhancement is not trivial because the resulting microstructure changes gradually from the surface to the bulk. Here we report a simple serial-sectioning technique to assess the hardness and corrosion behavior of a laser hardened chromoly steel at depth intervals of 30 μm. The method consists of indenting the sample surface to a controlled depth and then mechanically polishing the sample until the indents are no longer visible. By performing corrosion tests and recording the surface hardness at each depth interval, we assess the corrosion behavior and hardness of the material throughout the laser-induced microstructure gradient. Our measurements show that the improved corrosion resistance stems from the chromium-enriched oxide layer at the top surface of the steel alloy. Surprisingly, the phase content and grain size, whose distribution varies significantly throughout the sample thickness, has little to no effect on the corrosion behavior of the steel.

Surface oxidation, as one of fundamental chemical reactions in metals, greatly affects their properties. Herein, we develop a new quaternary GaInSnZn liquid metal with the melting temperature of 9.7 °C, which is the lowest among all reported Ga-based liquid metals. With high-resolution transmission electron microscopy, we directly observed the oxide layer formed on the surface of the liquid metal. The initially formed oxide layer is revealed to be amorphous and very sensitive to electron beam. Prolonged irradiation results in its structural change from amorphous to crystalline phases. The present finding refreshes the basic understanding of surface oxidization of liquid metals and opens up the possibility of tuning surface structures and morphologies by using electron beam irradiation.

A titanium oxide layer containing a small amount of Ni can be formed on a NiTi surface through anodization when using HNO 3 as an electrolyte. In this study, the effect of different HNO 3 concentrations on the surface characteristics of the alloy, including hydrophilicity, Ni-ion release, and antibacterial efficacy, was investigated. An oxide layer was fabricated, in which tiny pores were generated by pitting corrosion. The layer thickness and pore size varied with the concentration of the HNO 3 electrolyte. The hydrophilicity of the NiTi surface was dramatically improved through anodization owing to the formation of the oxide layer. The layer formed was expected to serve as a corrosion protection barrier; however, the Ni release rate from the anodized surface was higher than that of an untreated surface due to the generation of pores. The Ni release rate from the anodized surfaces varied depending on the electrolyte concentrations used, owing to the balance between the layer thickness and pore size. Ni ion release was advantageous from the view of antibacterial efficacies; the efficacies of NiTi alloy against E. coli and S. aureus were actually enhanced by anodization. Ni ion release was not beneficial with regards to allergenic reaction and cytotoxicity; the Ni ion release rate decreased rapidly when the alloy was soaked in a simulated body fluid. Thus, we concluded that anodization in HNO 3 is one possible approach to fabricate ideal NiTi medical devices with excellent antibacterial performance and biosafety.

A highly three-dimensional CdIn2S4 deposited TiO2 (CdIS/TONR/FTO) heterostructured photoanode has been fabricated via a two-step hydrothermal process to enhance the photoelectrochemical (PEC) performance. In this work, bare TiO2 nanorods are grown successfully on the fluorine-doped tin oxide (FTO) substrate via a hydrothermal method (TONR/FTO), and a second-step hydrothermal synthesis is used to grow CdIn2S4 flower nanostructured layer over the top surface of the bare TONR/FTO. Structural, morphological, optical, and elemental analysis of CdIS/TONR/FTO heterostructure photoanode is investigated in detail. PEC performances are studied in 0.2 V versus Ag/AgCl in mixed sulfide-based electrolyte for various concentrations of CdIn2S4 deposited on photoanodes. The photocurrent density for optimized (×4)-CdIS/TONR/FTO heterostructure photoanode is observed to be three times higher than that of the bare TONR/FTO photoanode. This excellent PEC performance is ascribed to the way that the deposited CdIn2S4 layer and TiO2 nanorods synergistically allow the absorption of a wide portion of the solar spectrum under back illumination, and provide efficient separation of the electron-hole pairs in the photoanode architecture. The EIS and IMPS analysis also reveal the significance of CdIn2S4 layer that provides the lowest charge-transfer resistance at the interface and high electron-transfer rate in CdIS/TONR/FTO photoanode. Mainly, the deposited CdIn2S4 layer significantly broadens the optical absorption capacity, and provides efficient electrons-holes transfer that reduces the recombination losses of the charge carriers. The proposed charge transfer mechanism in CdIS/TONR/FTO heterojunction is well studied.

Methylammonium lead iodide perovskites, CH3NH3PbI3, possess excellent photoelectric conversion properties and can be potentially applied as the next-generation light-harvesting layer of solar cells. However, the stability problems have been hindering their practical applications. The density-functional theory calculations have been performed to investigate the structural and electronic properties of Al-decorated TiO2/perovskite interfaces. Combined with the density derived electrostatic and chemical method, the bonding characteristics around the interfaces are explored. It is found that both interfacial Pb O and Ti I bonds are responsible for the stability of the interfaces, especially the interfacial Pb atoms making the formation of oxygen vacancies harder, which is beneficial for the performance of the solar cells. Furthermore, our calculations have shown that the properties of the TiO2/perovskite interfaces could be well improved by Al modification. The corresponding atomistic mechanisms that govern the stabilities of the TiO2/perovskite interfaces are also discussed.

A composite film was prepared by mixing NaLuF4:Yb3+/Er3+ up-conversion luminescent material with commercial P25, and a scattering layer composed of flower-like TiO2 was added on to the composite film (UC/P25) to form a double-layer composite film (UC/P25 + FT). An AgNO3 solution was irradiated by ultraviolet light to deposit nano-Ag particles on the prepared double-layer film, and a nano-Ag modified double-layer film (UC/P25 + FT + Ag) was finally obtained. The synergistic effect of the three improved methods conferred the UC/P25 + FT + Ag film with a wide spectral absorption range, strong light-scattering ability, and strong light absorption capability, which greatly improved the photoelectric performance of the film. The maximum photoelectron conversion efficiency of dye-sensitized solar cells with the UC/P25 + FT + Ag photoanode reached up to 8.14%, which increased by 32.36% compared with that of the pure P25 film photoelectrode.

Europium (Eu) and dysprosium (Dy) co-doped strontium aluminate (SrAl2O4) (SA:Eu,Dy) is one of the most widely applied long persistent phosphors due to its strong emission intensity and long afterglow. However, the difficulty to get crystalline SA:Eu,Dy thin films in the as-deposited state strongly limited their applications in devices and surface coatings. In this study, we present a breakthrough in the synthesis of single-crystal SA:Eu,Dy films via direct-epitaxial growth on sapphire substrate by means of pulsed layer deposition. A threshold temperature of 900 °C is identified, only above which the mobility of adatoms is high enough to form crystalline films. By avoiding the nucleation process via introducing a homo-buffer layer, this temperature can be significantly reduced by 200 °C. The direct-epitaxial growth ensures a good surface quality, while the temperature reduction may prevent interdiffusion in applications involving hetero multilayer structures. The films are single crystals composed of twinned domains. The constraint effect from substrate significantly limits the freedom for twinning, which leads to much less twin variants in films compared to powders. The high-quality epitaxial films obtained in this study are useful for understanding the unique phosphorescence mechanism in SA:Eu,Dy, which may further help to design new phosphor materials with higher performance.

A thin dielectric layer plays a significant role to extend the electronic and optical properties of graphene-based field effect transistors. This study investigates the interaction between graphene and aluminum oxide layer (Al2O3) and the influence of Al2O3 on the properties of graphene. The electrical characterization demonstrates the tunability in the resistivity of Al2O3/Gr devices by applying Vg. Al2O3 deposition introduced n-doping in graphene and is affirmed by shifting of charge neutrality point towards negative Vg. The selective coverage of channel, results in the formation of p-n junction within graphene FET which becomes more pronounced upon DUV treatment. Moreover, the study validates the modulation in interface properties of pristine GFET and Al2O3/Gr at different Vg and temperatures. An enhancement in the intervalley and phase coherence scattering rates is observed for Al2O3/Gr device. Therefore, the effect of dielectric layer on graphene based field effect transistors would be of great interest to tune the properties the device.

Hydrogen outgassing from a metal surface and a coated metal surface was visualized by two-dimensional mapping of hydrogen ions desorbed upon scanning electron beam irradiation. The samples used were stainless steel covered with a dense chromium oxide layer, and a reference surface of stainless steel. The coating layer was made by using the segregation phenomenon of the metal. Outgassing of hydrogen was detected from the holelike defects on the treated surface. However, hydrogen was not released from all the holelike defects seen in the SEM image. The outgassing positions were positions without chromium, but not all areas without chromium and/or oxygen coincided with outgassing positions.

Continuous, uniform, and sub-10 nm Al2O3 high-K dielectrics upon two-dimensional exfoliated multilayer MoTe2 are realized by atomic layer deposition (ALD) based on a nucleation layer (NL) prepared by the ozone-based process, interfacial AlN, and low-temperature (low-T) physical adsorption. The NLs gives rise to significant reduction of the leakage current in the sub-10 nm Al2O3 high-K dielectrics as shown by conductive atomic force microscopy. For the ozone-based NL, X-ray photoelectron spectroscopy (XPS) reveals the oxidation of MoTe2 which is detrimental to the electrical properties of MoTe2. For the AlN NL, XPS reveals that Mo N bonds were formed without Mo O bonds and no chemical shift appeared in Te-3d XPS spectrum, indicating the AlN NL did not result in the MoTe2 oxidation but instead the formation of an MoN layer. For the low-T NL, the XPS spectra of MoTe2 are the same as those of the as-exfoliated MoTe2 flake, consistent with the absence of chemical reactions during low-T physical adsorption. The result demonstrates that the NLs prepared by the low-T physical adsorption and the interfacial AlN are effective and favorable for nucleating high-quality high-K gate dielectrics on MoTe2 transistors.

For preparation of surface-enhanced Raman scattering (SERS) substrate with high stability, reproducibility, and sensitivity performances, graphene/Ag nanoparticles were chosen to make further improvement by introducing molecularly imprinted polymer (MIP) film to protect Ag nanoparticles. The thickness of the resulting ultra-thin MIP layer is 2 nm on the surface of Ag nanoparticles. The preparation of two-dimensional/core-shell structure SERS substrate (G/Ag@MIP) possesses high SERS activity toward the probe of bovine serum albumin (BSA) target molecule, which exhibits a 10 −12 M detection limit. The G/Ag@MIP shows good selectivity and recycle rate in the detecting process. These results show that the hybrid material as a SERS sensor is potential for medical diagnosis in life sciences.

The number and conductivity of active sites of electrocatalysts have become the main factors for excellent performances for hydrogen evolution reaction (HER). In this work, in situ formation of ultrathin C3N4 layers coating on the surface of metallic WO2 nanorods (WO2@C3N4) as electrocatalysts for HER has been realized by a facile dopamine (PDA) coating on WO3 nanorods precursor and following calcination process. Firstly, the uniform polydopamine (PDA) layer has been coated on the surface of WO3 nanorods (WO3@PDA) through a hydrogen thermal process. The ultrathin C3N4 layers with large graphitization degree after calcination of WO3@PDA can improve the conductivity and stability of catalysts during HER. The formation of one dimensional WO2 nanorods may expose more active sites for HER. Benefited from the synergistic effect between WO2 and C3N4 layers as well as the protection cap of ultrathin C3N4 layers, the obtained core-shell structured WO2@C3N4 nanorods exhibit excellent HER performances and high durability in acidic solution, which only require an overpotential of 98 mV to generate a current density of 10 mA cm−2. Therefore, this work provides a new strategy for constructing transition metal oxides electrocatalyst with high activity and stability by introducing ultrathin C3N4 layer coupled with 1D nanostructure.

High-performance vanadium dioxide (VO2) thin films with high luminous transmittance and solar modulation ability were successfully fabricated on ZrxOy/glass substrate by pulsed laser deposition. By controlling the growth temperature of the buffer layer, the stoichiometry and crystal structure of ZrxOy buffer layer can be converted from cubic Zr2O phase to monoclinic ZrO2 phase. Through such a transformation, the luminous transmittance (Tlum), solar modulation ability (ΔTsol), the transition temperature and the width of thermal hysteresis loop have been tuned without diminishing the thermochromic property. It is found that the insertion of ZrO2 layer results in a remarkable enhancement of the luminous transmittance and the solar modulation ability when compared to single-layer VO2 film. The findings in the present work may provide some new strategies for the commercialization of VO2 films in the field of smart energy-efficient windows.

Effect of nickel incorporation in diamond-like carbon (DLC) matrices has been investigated on the mechanical properties of Ni-DLC thin films by nanoindentation. DLC and Ni-DLC thin films of different nickel content were electrodeposited on ITO coated glass substrates at room temperature and low voltage. Raman spectrum analysis confirms the formation of the sp2 and sp3 phases of carbon in DLC and in some of Ni-DLC thin films. Microstructural studies by SEM reveal a variation in microstructures from finely granular to cluster like features with change in molar concentration of nickel in the electrolyte. GIXRD profiles demonstrate the presence of graphite, diamond and crystalline nickel phases in the thin films. EPMA study indicates the increase in nickel content in carbon matrix of prepared thin films with increase in nickel ions in the electrolyte. Depth controlled mode of nanoindentations was performed on the films to investigate their mechanical properties like hardness, elastic modulus, stiffness and elasto-plastic properties of the thin films. Nickel concentration dependent bilayer nature of heterogeneous growth structure has been revealed through force-distance curves. A hard and strong adhesive layer of DLC is formed immediately above the ITO surface, over which a much softer less adhesive layer is produced. With the increase in nickel content, bottom layer grows in thickness by the expense of the top layer. Hence at very low nickel content, the effect of top soft layer dominates the mechanical properties of the films, while at high nickel content gradually the effect of the soft layer vanishes. With increasing nickel content hardness of the films also shows an increasing trend contrary to the usual behavior of metal incorporated DLC thin films which may be due to multiple counter-interacting processes occurring simultaneously within the carbon matrix inducing changes in phase and hence in sp2/sp3 hybridization ratio.

Metallized polyimide (PI) film has great applications in the field of flexible electronics. Surface property adjustment is considered as an effective way to realize the metallization of PI film by chemical methods. In this work, we demonstrate a facile approach to fabricate metallized PI film via surface modification and electroless plating. Polyethyleneimine (PEI) cross-linked with glutaraldehyde (GA) is used as a modifier to act on the surface of alkali-treated PI film, and a special regular morphology is obtained. This PEI-modified PI film possesses not only functional groups for chemical bonding but also large surface roughness for mechanical locking with metallic copper layer. The resulting copper layer has low resistivity (2.30 μΩ·cm) and satisfactory adhesion to PI film (the highest score of 5B according to ASTM D3359), and the metallized PI sample exhibits reliable flexibility. These results demonstrate a promising potential of this approach in the field of PI film metallization with impact in wearables, light-weight, and flexible electronics.

SERS substrate containing SERS-active array of Ag, Au and Ag50Au50 nanoparticles with normal size distribution, a mirror layer and a separating SiO2 layer was optimized. A layer of amorphous carbon was used as the object of study. It is shown that such a structure enhances the Raman signal both due to the localized surface plasmon resonance and due to interference. The average size of nanoparticles, the reflection coefficient of mirror layer, and the thickness of SiO2 layer influence the amplification of the Raman signal. To provide amplification the thickness of SiO2 layer should be calculated for the appropriate wavelength in order to get constructive interference. It is revealed that additional amplification of the Raman signal occurs if the mirror layer as well as the array of particles is made of plasmon metal and thickness of separating SiO2 layer is quite small (up to 30 nm).

As a highly conductive and transparent electrode, ITO/Ag/ITO multilayers are fabricated using an in-line sputtering method. Optimal thickness conditions have been investigated in terms of optical transmittance and electrical conductance. Considering the optical properties, the experimental characteristics are analyzed based on theoretical phenomena and compared with the simulated results. The simulations are based on the finite-difference-time-domain (FDTD) method in solving linear Maxwell equations. The results showed that ITO/Ag/ITO structures with respective thicknesses of 39.2 nm/10.7 nm/39.2 nm are most suitable with an average transmittance of 87% calculated for wavelengths ranging from 400 to 800 nm and a sheet resistance of about 7.1 Ω∕□. However, even with the optimum thickness conditions of the ‘ITO/Ag/ITO’ multilayers, the transmittances on some ranges of the visible wavelength were much lower than those of a single ITO layer. In order to improve the transmittance, Ag layer was formed with mesh structure. The transmittance and the sheet resistance in the ITO/Mesh-Ag/ITO multilayer structure were analyzed depending on the open ratio. As a result, a trade off in the open ratio was necessary in order to obtain the transmittance as high as possible and the sheet resistance as possible low. By the experiments, we found out that the transmittance was nearly same as the single ITO layer and the sheet resistance was about 30 Ω∕□ when the open ratio was about 85%.

In this paper, the multi-layered self-healing thermal barrier coatings (TBCs) have been fabricated by atmospheric plasma spraying (APS). The phase composition of the sprayed feedstock and the as-sprayed coating have been characterized. The thickness of each layer for the self-healing TBCs have been optimized based on previous finite element simulation results. The self-healing effect of the TBCs under burner rig test (BRT) has been characterized via in-situ acoustic emission technique. The self-healing ability of the TBCs has been also characterized via static high temperature oxidation test. The investigation results indicate that the thickness of each layer for the as-sprayed self-healing TBCs is nearly in our optimization range based on our previous work. The AE signals of the TBCs before and after self-healing are distinctly different. When the self-healing effect has appeared, some key AE signals for the crack propagation has disappeared. The AE signals which are located at the higher frequency have been inhibited at a certain degree. The static high temperature oxidation results indicate that the TBCs with self-healing effect has lower oxidation rate compared with that of the TBCs without self-healing. The effective thickness of the TGO layer for the TBCs with self-healing treatment is lower compared with that of the TBCs without self-healing treatment.

The HVOF-sprayed NiCoCrAlYTa coating would generate a dense oxidative layer under high temperature so that the microstructure, chemical component, mechanical properties and high-temperature tribological behaviors of the coatings surface were changed significantly. The as-sprayed NiCoCrAlYTa coating is mainly composed of the phases of γ-Ni and β-NiAl as well as γ′-Ni3Al. The Al-rich phase of β-NiAl in the post-oxidized coating has disappeared, replaced by the emergence of α-Al2O3. The formation of the oxidative layer with α-Al2O3 columnar crystal could greatly improve the mechanical properties of the NiCoCrAlYTa coating. Along with the elevated temperature, the friction coefficient and wear rate of as-sprayed coating gradually decreased, and the primary mechanism changed from abrasive wear to adhesive wear. Although the friction coefficient of the post-oxidized coating is slightly higher than that of as-sprayed coating, the wear rate decreases, obviously. This is because the oxidative layer of post-oxidized coating exerts a great influence on the wear resistance, especially under the high temperature.

In order to enhance the bioactivity of the microarc oxidation (MAO) coating on titanium (Ti), a rapid modification technique of microwave hydrothermal (MH) treatment was used to form the dense, uniform and abundant hydroxyapatite (HA) crystals on the MAO coating surface. During the MH treatment, the calcium (Ca) and phosphorus (P) elements were migrated from the inner layer to the outer layer, creating the Ca2+ and PO43− ions, then reacted with the OH− ions in the NaOH aqueous, thus forming the HA crystals on the MAO coating surface within several minutes. With the increasing of the MH treatment time (15 and 60 min), the amounts of Ca and P elements in the MAO coating were greatly reduced according to the energy dispersive X-ray spectroscopy (EDS) results. Meanwhile, lots of Na0.23TiO2 nanoflakes were formed due to the chemical reaction between TiO2 and NaOH. The MAO coating after the MH treatment for 10 min showed a higher surface hardness and Young's modulus on the modified coating surface due to the formation of the dense and abundant HA crystals. Moreover, the MH treated MAO coatings showed rough and porous surfaces, good surface wettability, high surface energy and surface potential. The apatite formation ability of the MH treated MAO coating was significantly improved resulting from the formation of the abundant HA crystals.

Flake aluminum powders with excellent corrosive resistance properties are attractive materials in many technological applications. Here, a convenient strategy is employed to encapsulate the aluminum powders by using silicon-fluoropolymer composite film, by which the chemical resistance of aluminum-based pigments is significantly improved. A basic layer of SiO2 is formed on the surface of the flake aluminum powders via sol-gel process. For the good compatibility between the silicon and fluorine, a uniform and dense layer of poly (trifluoroethyl methacrylate) (PTFEMA) is pasted tightly on the silicon layer initially formed by solution polymerization. Protected by this kind of composite silicon-fluoro-layer, the encapsulated aluminum powders were highly stable when they dipped into strongly alkaline solution (1.25 M, pH > 14). The morphology of composite layers on the aluminum powders are characterized by means of scanning electron microscopy (SEM). The structures of silicon-fluoropolymer composite film are tested by Fourier transform infrared spectroscopy (FTIR), energy dispersive spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS). The relationship between the usage of monomers and cross-linker on corrosion inhibition properties is systematically investigated. The phenomenon of hydrogen gas evolution is eliminated by the PTFEMA/SiO2 hybrid films owing to an efficient fluorinated protective film on aluminum pigments.

The electrical transport of ultrathin films is an issue for modern electronics, since conduction properties of commonly used metals present important differences for thicknesses in the nanometer scale. This report shows that the sheet resistance of gold ultrathin films (between 1.2 nm and 3.8 nm) decreases up to 5 orders of magnitude when a chromium layer 0.8 nm thick is used as surfactant. The chromium layer changes the morphology of the gold films on mica, composed by large isolated grains, allowing the formation of a population of small grains between the large ones, therefore reducing the thickness at which the electrical percolation is achieved. The electrical percolation thickness, evidenced as a sharp decay in sheet resistance, occurs at 3.9 nm, for gold deposited directly on mica, while this value is reduced to 1.2 nm if a thin chromium layer is previously grown on the mica substrate. A deeper study of the electrical properties of this gold ultrathin films grown on Cr/mica show that above 2.8 nm, they already present a metallic behavior; while films near 2.2 nm show a zero temperature coefficient, meaning that the electrical conduction driven by tunneling still plays an important role in the electronic transport. Finally, is demonstrated, that the contribution of the chromium layer to the electrical conductivity of films can be neglected. Namely the influence of the chromium layer on metallic ultrathin films, is mainly as a surfactant, with no direct role in the electronic transport itself.

Adding the two-dimensional (2D) material into the metal/oxide interface is a novel method to tune the property of the interface and the interface-controlled device. Compared to the widely studied influence of the interfacial 2D-material on the kinetic diffusion of the atom across the interface, the effect of the interfacial 2D layer on the energetic behavior of the point defect at the interface viewed at the electronic-/atomic-scale is less focused. In this work, the influence of graphene on the Au/HfO2 interface is studied using a first-principles calculation. It is found that graphene can eliminate the Au-induced insulator-metal-transition of the HfO2 layer at the interface, by screening the strong interaction between Au and HfO2. At the atomic scale, graphene significantly increases the formation energy of the oxygen vacancy and vacancy pair in HfO2 at the Au/HfO2 interface, making the interfacial HfO2-layer surface-like. Also graphene alleviates the valence-electron-number dependent segregation of the alloying elements Ag, Cu and Ta at the Au/HfO2 interface. The significant impact of graphene at the metal/oxide interface unraveled from the energetic point of view provides an alternative insight into the interface engineering of the electronic device such as the oxide-based resistive random access memory.

Diamond film has been deposited on stainless steels using hot filament chemical vapor deposition by applying Al/AlSiN as interlayer to improve the adhesion strength. The results show that diamond film exhibits good adhesion performance in the case of 3.4 at.% of Si contained in the AlSiN interlayer. Moreover, the film is smooth with small roughness of Ra 58.3699 nm. Grazing incidence X-ray diffraction pattern indicates that AlSiN solid solution has been formed, which prefers more carbon atoms to diffuse into the AlSiN layer. Accompanying by the diffusion of chromium atoms from the steel substrate into the interlayer, more chromium carbide formed at Al/AlSiN interface, which strengthens the weakest point of the film by decreasing stress concentration and providing mechanical interlocking, improving the adhesion of diamond film. At Si content equal to or higher than 5.4 at.% in the interlayer, amorphous Si3N4 precipitates at the grain boundaries, which decreases the volume of grain boundaries, resulting in the decrease of carbon diffusion rate. Consequently, a small number of carbides form at Al/AlSiN interface, weakening the adhesion of the film.

Organic-inorganic perovskite solar cells (PSCs) have achieved high power conversion efficiency (PCE) over the last few years. However, interfacial recombination of PSCs and the defects of perovskite film still seriously restrain the performance of PSCs. Hence, we introduced PbS quantum dots (QDs) between perovskite layer and hole transport layer (HTL) to modulate delicately both the interfacial contact and the perovskite film. With the incorporation of PbS QDs, the PSCs presented enhancement in hole extraction and retardation in interfacial recombination. Besides, proper concentration of PbS QDs contributed to improved perovskite film morphology by enlarging the grain size and healing the pinholes. Benefiting from all of these advantages, devices with PbS QDs modification achieved an impressive PCE of 19.24%, superior to that fabricated without the modification.

Two-dimensional (2D) layered materials have unique electromechanical properties in contrast to their bulk counterparts. In particular, the out-of-plane piezoresponse of 2D layered materials is still veiled according to their properties and mechanisms, whereas the in-plane piezoelectricity has been well confirmed. Herein, a large-area MoS2 monolayer was deposited on a SiO2/Si substrate by chemical vapor deposition, and subsequently, it was transferred to a flexible plastic substrate. The number of MoS2 layers (1L, 2L, and 3L) was controlled by the synthesis time (10, 20, and 30 min). The layer number of MoS2 was confirmed using Raman and photoluminescence spectra. To focus on the piezoelectric property of the 2D material, we observed the surface morphology of the MoS2 monolayer consisting of both large-corrugated and small-corrugated regions using atomic force microscopic characterization. Piezoresponse force microscopic measurements revealed that the out-of-plane surface charge distribution of the MoS2 monolayer was attributed to the corrugation of the MoS2 layer. Further, the local piezoresponse of the MoS2 showed that the out-of-plane piezoelectricity can be invoked by flexoelectric effects. This study shows the possibilities of controlling the synthesis and piezoelectricity of large-area 2D materials for piezoelectric applications.

Perovskite compound-based solar cells using metal free phthalocyanine, silicon phthalocyanine or germanium naphthalocyanine complexes were fabricated and characterized for improving the photovoltaic performance. Additive effects of metal free phthalocyanine, silicon phthalocyanine or germanium naphthalocyanine complexes into the methyl ammonium‑lead-halide perovskite layer on the photovoltaic properties were investigated. The slight addition of the silicon phthalocyanine into the perovskite layer caused suppression of defect and pinhole in the surface layer, which had the best photovoltaic performance. The phthalocyanine complexes play an important role for improving the crystal growth, carrier generation and diffusion without carrier recombination and trapping near the defect and pinhole in the perovskite layer.

In this work we studied the main surface characteristics together with the in vivo osseointegration of three Zr-Ti alloys with hydroxyapatite-zirconia-silver (HAP-ZrO2- Ag) coating layer. The main purpose was to provide a quantitative evaluation and interpretation from micro to nano scale of the processes involved in the osseointegration of the HAP-ZrO2-Ag coated Zr-Ti specimens in a pig model. The surface characteristics were studied by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD). After the insertion of the implants into pig tibia, the osseointegration was investigated by means of biochemical analysis as well as bone histomorphometric and computed tomography measurements. The results of this in vivo study sustains that the capacity of the Zr-Ti specimens coated with HAPZrO2- Ag to promote osteogenesis is significant during the first month after implantation as compared with the control, being influenced by the interactions between bone tissue and HAP-ZrO2-Ag surfaces, but also by the chemical composition of the alloys.

Transient liquid phase (TLP) bonding of Inconel 718 with BNi-2 filler metal has traditionally been carried out using thin filler metal (narrow gap) to achieve complete eutectic-free isothermal solidification layer joints. However, for the aerospace components with relatively large cracks or worn areas where a large amount of filler metal is needed, narrow gap TLP bonding is insatiable to meet the bonding requirements. In this paper, wide gap TLP bonding of Inconel 718 with the BNi-2 paste filler metal was carried out in a vacuum furnace. The bonding temperature effects on the interfacial microstructure, phase evolution and the mechanical properties of the bonded joints were investigated. It was found that the ultimate tensile bonding strength increased by 98% as the bonding temperature increased from 1015 °C to 1150 °C and the joint with the maximum tensile strength of 482 MPa was achieved after bonding at 1150 °C for 15 mins. However, more adverse heating was induced on the base metal of the joint under a higher bonding temperature. In addition, increasing bonding temperature from 1015 °C to 1150 °C improved the local plasticity of the bonded joints owing to the reduction of the homogeneously distributed Ni₃B type borides to a more heterogeneous distribution of borides. National Research Foundation (NRF) This work was conducted within the Rolls-Royce@NTU Corporate Laboratory with the support from National Research Foundation (NRF) Singapore under the NRF-RR-NTU research grant number M-RT3.2.

Graphene is a hydrophobic material and cannot be used for the formation of multilayer coatings with the conventional layer-by-layer (LbL) technique. In our work, we proposed to use for that purpose the suspension of graphene oxide (GO) and to reduce it to the reduced graphene oxide (rGO). GO is negatively charged, and as easily suspended in water, it can be used as an anionic layer together with some cationic polyelectrolytes for the multilayer film formation. The several reduction methods were compared to transform GO towards reduced graphene oxide (rGO), e.g., UV illumination, thermal reduction and chemical reduction using hydrazine. It can be observed that thermal reduction of GO above the temperature 180 °C was the most effective process leading to the formation of sp2-hybridized carbon atoms and can be directly applied for GO containing films. The XPS spectra showed that after the reduction process the ratio of the sp2 carbon increased to c.a. 80 at.%. The structure and properties of the coatings before and after reduction were studied using UV–Vis, spectroscopic ellipsometry and scanning electron microscopy (SEM). We demonstrated that it was possible to get thin rGO conductive films on quartz and polyimide (PI) plates measuring surface conductivity with the use of the four-point method. The building of films on PI allows creating flexible new materials, which may be applied in biomedicine as, e.g., electroactive sensors.

In this work, memristors based on TiO2 nanorod arrays (TNAs) were fabricated using a hydrothermal synthesis method. The memristors had a structure consisting of a TNA sandwiched between gold and fluorine doped tin oxide (FTO) coated glass. Devices were constructed using TNAs containing nanorods of different height, diameter and area ratio, with different oxygen vacancy concentrations. The devices exhibit resistance switching behavior and the current through the devices is related to the oxygen vacancy concentration and the area ratio of TNAs. When the height of nanorods is around 3 μm or less, the devices perform well with a current that is as low as 10−8 A in the high resistance state (HRS) and 10−4 A in the low resistance state (LRS). It is found that the space charge limited current (SCLC) mechanism associated with the oxygen vacancies explains the current-voltage behavior of these devices in this three layer structure. A schematic model is presented to illustrate the changes in oxygen vacancy concentration and switching processes, including the formation of new oxygen vacancies (triggered vacancies) to explain the large increase in current at the end of the setting process in these devices.

In this work, two methods were proposed to improve the bonding quality of Ag sinter joining on Au surface finished substrate (Ag Au joint). The first method was preheating treatment to Au surface finished substrate before sintering. The second method proposed was increasing the initial thickness of the Au layer on the substrate. The bonding strength of the sintered specimen improved from 13.8 MPa to 25.4 MPa by a 250 °C substrate preheating treatment. Also, bonding strength increased from 13.3 MPa to 24.4 MPa as the initial thickness of Au layer was increased from 0.1 to 0.8 μm. SEM, EDS and XRD characterizations were conducted to analyze improvement of bonding strength, diffusion behavior between Au and Ag, and structure of Au layer. The results indicated that the enhancement of bonding strength was attributed to the increase of Au grain-size because larger Au grains can alleviate grain boundary diffusion that can diminish bonding strength. As a result of this finding, an empirical equation that indicates the correlation between bonding strength and Au grain-size was also proposed.

The oxidation behavior of a single-crystal Ni-based superalloy over the temperature range of 850 °C–950 °C and under Ra = 0.1–0.2 μm was investigated. The oxidation kinetics of the superalloy presented two stages. The first and second stages had activation energies of 222 and 263 KJ·mol−1, respectively. The oxide film comprised NiO, NiCr2O4, CrTaO4, and Al2O3. The formation time of the continuous Al2O3 layer corresponded to the transition point of oxidation kinetics at each temperature. Mass gain in the first stage could be attributed to the formation of an outer NiO layer and an inner alumina layer, whereas that in the second stage could be ascribed to the growth of intermediate spinel layers.

In this work, we present a combined method to produce a superhydrophobic ceramic coating on carbon steel. A hot-dip aluminizing approach is proposed for fabricating an aluminum coating on the carbon steel surface. This aluminum coating is anodized to produce a ceramic oxide layer. The ceramic coating is identified as a mixture of α-AlOOH, γ-AlOOH and γ-Al2O3. The XRD analysis indicates that the ceramic coating is poorly crystalline. The ceramic coating exhibits a patterned surface with nano-pores and nano-wires. Due to this structured surface, the ceramic coating shows superhydrophobicity after reducing surface energy by using a chemical treatment.

Recently, demands for magneto-optical (MO) materials with high laser-induced damage thresholds (LIDT) increased rapidly with the continuous development of high power lasers. In order to study the effect of substrate defects on LIDT of (BiTm)3(GaFe)5O12 films, in this study, (BiTm)3(GaFe)5O12 films without gadolinium gallium garnet (GGG) substrates and (BiTm)3(GaFe)5O12/GGG films were prepared by liquid-phase epitaxial (LPE) and mechanical lapping and polishing method. The optical and magneto-optical properties, crystal structure, LIDT and laser-induced damage morphologies of the prepared films were investigated. Experimental results pointed out that epitaxial (BiTm)3(GaFe)5O12 films have very high crystal and surface quality. A discontinuous defective layer with thickness of about 0–500 nm is located between GGG substrates and epitaxial films. Laser-induced damage tests and damage morphologies demonstrate that the discontinuous defective layers have an important effect on LIDT of epitaxial films, and LIDT of epitaxy films can be significantly improved by removing GGG substrates and discontinuous defective layers.

Organic residues formed when using organic binders to increase the adhesive strength of Cu ink to PI substrates degrade the electrical conductivity of Cu electrodes. Binder-free Cu ink can be used to fabricate highly conductive Cu electrodes but lead to poor adhesion owing to inherently weak adhesion between the polymer substrates and metals. We therefore propose a facile method to enhance adhesion between a printed copper electrode formed by flash light sintering and a polyimide (PI) substrate without sacrificing the electrical conductivity by forming an interlocking structure at the interface between the Cu electrode made of binder-free ink and PI substrate through simple chemical treatment. The surface of the PI substrate was converted to polyamic acid (PAA) via potassium polyamate formation after sequential chemical treatment using potassium hydroxide and hydrochloric acid. During the flash light sintering process, the PAA layer, which is much softer than PI, could easily migrate into the cavities between the sintered Cu nanoparticles due to the pressure difference originating from evaporation of H2O released through reduction of the oxide shell of Cu nanoparticles. Thus, an interlocking structure was formed and the substrate surface quickly reverted to PI by absorbing thermal energy during sintering. The increased contact area between Cu nanoparticles and the substrate surface of the interlocking structure could explain the dramatic improvement of the adhesion strength of the Cu electrode from 0 B to 5 B, which corresponds to the highest class of adhesion strength. In addition, the resistivity of the Cu electrode fabricated in this process was measured to be 2.5 times larger (4.17 μΩ·cm) than that of bulk Cu, which has not been achieved for printed Cu electrodes before. Our results could lead to new perspectives in the field of printed electronics.

VC carbides are the common strengthening phases in the hot-work die steels containing V element, and gas nitriding is a popular thermo-chemical surface treatment, which has been using to improve thermal/mechanical fatigue and wear resistance of steels. In this study, the effects of VC precipitation on the hardness, thickness and wear resistance of the nitrided layer in AISI H13 hot-work die steel were systematically investigated. The results showed that a part of carbon atoms in the fine VC carbides were replaced by the nitrogen atoms during nitriding at 550 °C and some nitrogen were released to the matrix when the sample was cooled down to room temperature, so as to promote the hardness of the diffusion layer. Besides, VC precipitation promoted the diffusion of nitrogen by decreasing the C and V concentrations in the matrix, which decreased the diffusion activation energy of nitrogen in the matrix and made the diffusion layer thicker. Moreover, the thicker and harder nitride layer improved the wear resistance of the sample at a load of 100 N.

The aim of present paper was to study the microstructural evolution and the high-temperature high-pressure corrosion behavior of N18 zirconium alloy prior and after high-current pulsed electron beam (HCPEB) surface irradiation. Observations of microstructures showed that after HCPEB irradiation, the surface layer of the sample was melted, inside which gradually refined grains, martensites and their internal twin substructures were obtained. Meanwhile, second-phase particles (SPPs) were dissolved into the matrix within the modified layer, and alloying elements Fe, Cr, Nb were supersaturated in Zr-based solid solution. Besides, high residual compressive stress was unceasingly accumulated in the surface layer with the increasing of pulses. After exposed at 500 °C/10.3 MPa superheated steam for 30 days, the corrosion resistance of multiple-pulsed samples, particularly the 25-pulsed one, was obviously higher than that of the initial sample. The combined action of high residual compressive stress, supersaturated alloying elements, selective purification effect and abundant structure defects in the modified layer helped improve the corrosion resistance.