Research

17 pages, 7705 KiB

Open AccessArticle

Effect of Annealing on Stress, Microstructure, and Interfaces of NiV/B₄C Multilayers

by Chenyuan Chang, Zhenbo Wei, Hui Jiang, Hangjian Ni, Wentao Song, Jialian He, Simeng Xiang, Zhanshan Wang, Zhe Zhang and Zhong Zhang

Coatings 2024, 14(4), 513; https://doi.org/10.3390/coatings14040513 - 20 Apr 2024

Viewed by 222

Abstract

The functionality and reliability of nanoscale multilayer devices and components are influenced by changes in stress and microstructure throughout fabrication, processing, and operation. NiV/B₄C multilayers with a d-spacing of 3 nm were prepared by magnetron sputtering, and two groups of annealing [...] Read more.

The functionality and reliability of nanoscale multilayer devices and components are influenced by changes in stress and microstructure throughout fabrication, processing, and operation. NiV/B₄C multilayers with a d-spacing of 3 nm were prepared by magnetron sputtering, and two groups of annealing experiments were performed. The stress, microstructure, and interface changes in NiV/B₄C after annealing were investigated by grazing-incidence X-ray reflectometry (GIXR), grazing-incidence X-ray diffraction (GIXRD), X-ray diffuse scattering, and grazing-incidence small-angle X-ray scattering (GISAXS). The temperature dependence experiments revealed a gradual shift in the multilayer stress from compression to tension during annealing from 70 °C to 340 °C, with the stress approaching near-zero levels between 70 °C and 140 °C. The time-dependent experiments indicated that most of the stress changes occurred within the initial 10 min, which showed that prolonged annealing was unnecessary. Combining the X-ray diffraction and X-ray scattering measurements, it was found that the changes in the thickness, interface roughness, and lateral correlation length, primarily due to crystallization, drove the changes in stress and microstructure. Full article

(This article belongs to the Special Issue Thin-Film Synthesis, Characterization and Properties)

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21 pages, 4682 KiB

Open AccessArticle

Electrodeposition of Nanostructured Co–Cu Thin Alloy Films on to Steel Substrate from an Environmentally Friendly Novel Lactate Bath under Different Operating Conditions

by Raiedhah A. Alsaiari, Medhat M. Kamel and Mervate M. Mohamed

Coatings 2024, 14(4), 407; https://doi.org/10.3390/coatings14040407 - 29 Mar 2024

Viewed by 510

Abstract

A new lactate bath was proposed to deposit Co–Cu thin alloy films in nanostructure form onto a steel cathode. The deposition bath contained CuSO₄.5H₂O, CoSO₄.7H₂O, CH₃CHOHCOOH, and anhydrous Na₂SO₄ at [...] Read more.

A new lactate bath was proposed to deposit Co–Cu thin alloy films in nanostructure form onto a steel cathode. The deposition bath contained CuSO₄.5H₂O, CoSO₄.7H₂O, CH₃CHOHCOOH, and anhydrous Na₂SO₄ at pH 10. The effects of [Co²⁺]/[Cu²⁺] molar ratios, lactate ion concentration, current density (CD), and bath temperature on cathodic polarization, cathodic current efficacy (CCE), composition, and structure of the Co–Cu alloys were investigated. The new bath had a high cathodic current efficiency of 85%, which increased with the applied CD. However, it decreased as the temperature increased. The produced coatings have an atomic percentage of Cu ranging from 19.8 to 99%. The deposition of the Co–Cu alloy belonged to regular codeposition. The Co content of the deposit increased with the amount of Co²⁺ ions in the bath, lactate concentration, and current density but decreased as the temperature increased. Cobalt hexagonal close-packed (HCP) and copper-rich, face-centered cubic (FCC) Co–Cu phases combine to form the polycrystalline structure of the electrodeposited Co–Cu alloy. The average crystallite size ranges between 46 and 89 nm. An energy dispersive X-ray (EDX) examination confirmed that the deposit contained Cu and Co metals. The throwing power and throwing index of the alkaline lactate bath were evaluated and found to be satisfactory. Full article

(This article belongs to the Special Issue Thin-Film Synthesis, Characterization and Properties)

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10 pages, 6005 KiB

Open AccessArticle

Feasible Parameters of Ohmic Areas of YBaCuO Thin Films Switched via Moving Unstable Border between Superconducting and Normal States

by Linas Ardaravičius and Oleg Kiprijanovič

Coatings 2024, 14(3), 266; https://doi.org/10.3390/coatings14030266 - 22 Feb 2024

Viewed by 692

Abstract

A system of two equations based on one of the classical electricity laws was used to determine the sizes and temperatures of ohmic areas formed under action of overcritical nanosecond electrical pulses. Calculations were performed at five points for three experimentally obtained voltage–current [...] Read more.

A system of two equations based on one of the classical electricity laws was used to determine the sizes and temperatures of ohmic areas formed under action of overcritical nanosecond electrical pulses. Calculations were performed at five points for three experimentally obtained voltage–current (V-I) dependences for samples with the same geometry but different critical current density values. The system included two additional conditions to satisfy the known descriptive model of transition from superconducting (SC) to a normal (N) state—S-N switching—and to obtain physically acceptable solutions over the entire current range of V-I dependence. The solution for each point takes the form of a function, since the initial temperature increase of the primary channel across the film is entered as a parameter. Two modes of concentrated energy release in the channel were disclosed. Their random appearance leads to an unexpected degradation of the sample. As such, the obtained results correspond to the situations occurring during the experiments. The validity of applying additional conditions to the system is discussed. In the discussion, it is also explained at which moments the moving S-N border acquires the velocity of the order of ~10⁶ m/s, comparable to the Fermi velocity. Consideration to describe the moving unstable S-N border as being constantly in a state of Richtmyer–Meshkov instability is presented. Full article

(This article belongs to the Special Issue Thin-Film Synthesis, Characterization and Properties)

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10 pages, 1932 KiB

Open AccessArticle

Dependence of Nucleation Field on the Size of Soft Phase in Magnetic Hard–Soft Exchange Coupling Nanocomposites

by Fang Wang, Guoqi Hu, Pengna Zhang, Tangfu Feng, Yajuan Wang, Renbing Sun and Jian Zhang

Coatings 2024, 14(2), 219; https://doi.org/10.3390/coatings14020219 - 10 Feb 2024

Viewed by 662

Abstract

Hard–soft exchange coupling nanocomposites have critical applications in various important materials. The magnetic properties of nanocomposite permanent magnetic films improve with a higher nucleation field (H_ns) of the soft magnetic phase. H_ns is sensitive to the thickness (d_s) [...] Read more.

Hard–soft exchange coupling nanocomposites have critical applications in various important materials. The magnetic properties of nanocomposite permanent magnetic films improve with a higher nucleation field (H_ns) of the soft magnetic phase. H_ns is sensitive to the thickness (d_s) of the soft magnetic layer. Understanding the dependence of H_ns and irreversible field (H_irr) on d_s, especially at the nanometric scale, is crucial for comprehending the magnetic mechanism and facilitating the design and preparation of high-performance nanocomposite permanent magnets. However, during the high-temperature deposition process, diffusion between hard and soft magnetic phases occurs, leading to the generation of other phases. This makes it challenging to accurately reflect the relationship between H_ns and d_s. To address this issue, we successfully fabricated high-quality SmCo₅/Fe nanocomposite bilayer films with different soft magnetic thicknesses and high textures by controlling the preparation process. We conducted a quantitative analysis of the relationship between H_ns and d_s within the range of 2–40 nm. Based on the experimental results, we propose a new theoretical simulation formula that enhances the understanding of the characteristics at the interface between the soft magnetic and hard magnetic phases. The theoretical simulation results show that a thin softened hard layer of about 4–6 nm thickness exists at the interfacial region, which concurrently reverses with the soft magnetic phase during the demagnetization process. Our results offer the generality and critical basis for the further study of hard–soft nanocomposite magnetic materials. Full article

(This article belongs to the Special Issue Thin-Film Synthesis, Characterization and Properties)

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17 pages, 916 KiB

Open AccessArticle

Temperature Coefficient of Electronic Polarizability in Thin Polymer Films Deposited on Si and SiO₂ Substrates Determined via Spectroscopic Ellipsometry

by Henryk Bednarski, Barbara Hajduk, Paweł Jarka and Pallavi Kumari

Coatings 2024, 14(2), 166; https://doi.org/10.3390/coatings14020166 - 27 Jan 2024

Cited by 1 | Viewed by 868

Abstract

Ellipsometry is widely used to determine the thermo-optical properties of thin polymer films. However, if the thermo-optic coefficient (TOC) and the linear thermal expansion coefficient (LTEC) are to be used to determine the temperature coefficient of electronic polarizability (TCEP) in thin polymer films, [...] Read more.

Ellipsometry is widely used to determine the thermo-optical properties of thin polymer films. However, if the thermo-optic coefficient (TOC) and the linear thermal expansion coefficient (LTEC) are to be used to determine the temperature coefficient of electronic polarizability (TCEP) in thin polymer films, their values must be determined with the greatest possible accuracy, as both have the opposite effect. In this article, we analyze changes in ellipsometric parameters resulting from changes in the thin film temperature in order to develop a data analysis method for temperature-dependent spectroscopic ellipsometry that will facilitate the accurate determination of thermo-optical parameters, including the TCEP, in polymer thin films. As practical application examples, we identified optimal spectral windows to accurately determine the thermo-optical parameters of 50 to 150 nm-thick PMMA thin films deposited on Si and SiO₂ substrates. The influence of thin-film thickness on the accuracy of TOC and LTEC determination is discussed. Full article

(This article belongs to the Special Issue Thin-Film Synthesis, Characterization and Properties)

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13 pages, 6007 KiB

Open AccessArticle

Improvement of the Electrocatalytic Properties for the Methanol Oxidation Reaction (MOR) of the CoPt Alloy

by Oana-Georgiana Dragos-Pinzaru, Luiza Racila, Gabriela Buema, Ibro Tabakovic and Nicoleta Lupu

Coatings 2024, 14(1), 17; https://doi.org/10.3390/coatings14010017 - 23 Dec 2023

Viewed by 1088

Abstract

The commercialization of the Direct Methanol Fuel Cell (DMFC) is limited due to the high cost and low efficiency of the electrocatalysts. In this context, the development of new electrocatalysts able to efficiently oxidize the methanol and to have at the same time [...] Read more.

The commercialization of the Direct Methanol Fuel Cell (DMFC) is limited due to the high cost and low efficiency of the electrocatalysts. In this context, the development of new electrocatalysts able to efficiently oxidize the methanol and to have at the same time low price and high stability is one of the researcher’s milestones. In this work, CoPt alloys with different Pt content were prepared, and the efficiency of the alloys to be used as electrocatalysts for the methanol oxidation reaction (MOR) was investigated. Our data show that the electrocatalytic performance of the CoPt electrodeposited alloys is strongly influenced by the synthesis conditions, mainly by the potential applied during the synthesis. The best electrocatalytic activity was obtained for the samples prepared at −0.8 V/SCE. Full article

(This article belongs to the Special Issue Thin-Film Synthesis, Characterization and Properties)

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15 pages, 2975 KiB

Open AccessArticle

High-Performance Polyimide Films Derived from Biomass-Based Furfural: Fabrication and Properties

by Lei Chen, Weiyu Luo, Yima He, Lizhen Huang, Jinjie Xu, Kaixin Li and Yonggang Min

Coatings 2023, 13(10), 1726; https://doi.org/10.3390/coatings13101726 - 03 Oct 2023

Viewed by 904

Abstract

The development of renewable polymers as alternatives to the petroleum-based ones has received significant attention due to the increasing depletion of fossil oil and the associated environmental concerns. In this study, a semi-biomass-based polyimide (PI) film was successfully synthesized, using biomass-derived furfural (HMFA) [...] Read more.

The development of renewable polymers as alternatives to the petroleum-based ones has received significant attention due to the increasing depletion of fossil oil and the associated environmental concerns. In this study, a semi-biomass-based polyimide (PI) film was successfully synthesized, using biomass-derived furfural (HMFA) as one of the raw materials. A two-step approach was first developed for this process: (1) conversion of HMFA to 3,3,4,4-biphenyltetracarboxylic acid dianhydride (BPDA) and (2) polymerization of BPDA with p-phenylenediamine (PPD) to form a PI film. The fabricated PI film demonstrated excellent properties, such as a high thermal decomposition temperature up to 600 °C, a satisfactory glass transition temperature (Tg) exceeding 365 °C, a coefficient of thermal expansion (CTE) of ≈30 ppm/K, a tensile strength greater than 120 MPa, a dielectric constant value below 3.4, a dielectric loss value of less than 0.02, and a 24 h water absorption rate below 0.8%. These performances are comparable to the petrochemical-based PI. This work offers a promising strategy for utilizing biomass-derived materials in polyimide synthesis and would drive a new wave of advancements in polymer science. Full article

(This article belongs to the Special Issue Thin-Film Synthesis, Characterization and Properties)

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10 pages, 2845 KiB

Open AccessArticle

Paramagnetic Properties of Carbon Films

by Bagila A. Baitimbetova, Yuri A. Ryabikin, Bagdat A. Rakymetov, Danatbek O. Murzalinov, Dinara O. Kantarbaeva, Bahat Duamet, Elena A. Dmitriyeva, Abay S. Serikkanov and Kassym Yelemessov

Coatings 2023, 13(9), 1484; https://doi.org/10.3390/coatings13091484 - 22 Aug 2023

Cited by 1 | Viewed by 757

Abstract

This research paper presents the results of obtaining carbon films on various substrates (quartz, mica, and silicon) at temperatures from 0 °C (initial) to 800 °C through plasma chemical vapor deposition. The carbon films obtained on various films were studied using the method [...] Read more.

This research paper presents the results of obtaining carbon films on various substrates (quartz, mica, and silicon) at temperatures from 0 °C (initial) to 800 °C through plasma chemical vapor deposition. The carbon films obtained on various films were studied using the method of electron paramagnetic resonance (EPR). EPR measurements were carried out on twenty samples at a perpendicular and parallel arrangement of the sample plane concerning the orientation of the magnetic field. When measuring the resonance conditions by changing the magnetic field, an EPR signal appeared in all of the deposited samples. The paper presents a general view of the EPR spectrum in all of the samples, including the signal intensity, g-factor, line widths, and normalized signal intensity of the carbon films on various substrates at temperatures from 0 °C to 800 °C. Studies show that with an increase in temperature, the normalized intensity of the EPR signal line increases during the deposition of a carbon in all deposited substrates (quartz, mica, and silicon) using the method of plasma decomposition of a mixture of methane and hydrogen. Full article

(This article belongs to the Special Issue Thin-Film Synthesis, Characterization and Properties)

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11 pages, 2587 KiB

Open AccessArticle

Fabrication and Characterization of Mineral Hydrophilic Antifogging Film via Vacuum Evaporation Method

by Shenyu Wei, Qi Zheng, Lei Wang, Cheng Peng, Xinglan Cui, Xiaokui Che, Wuyu Wang and Zeen Yu

Coatings 2023, 13(4), 730; https://doi.org/10.3390/coatings13040730 - 03 Apr 2023

Cited by 2 | Viewed by 1252

Abstract

Natural silicate minerals have a wide range of applications as green, non-toxic and low-cost materials. In this paper, hydrophilic anti-fog films of silicate minerals were generated via a vacuum evaporation coating method using natural feldspar minerals as raw material. Thermogravimetric analysis shows that [...] Read more.

Natural silicate minerals have a wide range of applications as green, non-toxic and low-cost materials. In this paper, hydrophilic anti-fog films of silicate minerals were generated via a vacuum evaporation coating method using natural feldspar minerals as raw material. Thermogravimetric analysis shows that the feldspar changes its structure during the coating process, which in turn changes the roughness of the film and improves the hydrophilicity of the film. The hydrophilicity, anti-fogging properties, optical properties and surface morphology of the films were characterized by contact angle measurements, the hydrothermal method, UV-VIS spectrophotometer and atomic force microscopy, respectively. The results show that the mineral films have excellent hydrophilicity. The best anti-fog effect was achieved at a minimum contact angle of 22.3° with water when the thickness of the film was 100 nm. The anti-fog effect gradually decreased with the increasing thickness of the film. The optical transmittance test showed that the film material had a negligible effect on the transmittance of the substrate. When the film thickness was 100 nm, the maximum optical transmittance was 92.2%. This is 4.5% higher than when the film was uncoated, which has a specific visual transmittance effect. Full article

(This article belongs to the Special Issue Thin-Film Synthesis, Characterization and Properties)

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15 pages, 7623 KiB

Open AccessArticle

Vapor Deposited Zeolitic Imidazolate Framework-8 Derived from Porous ZnO Thin Films

by Marianne Kräuter, Katrin Unger, Roland Resel and Anna Maria Coclite

Coatings 2023, 13(4), 718; https://doi.org/10.3390/coatings13040718 - 31 Mar 2023

Cited by 1 | Viewed by 1288

Abstract

In recent years, the vapor deposition of zeolitic imidazolate framework-8 (ZIF-8) has gained high attraction due to its good scalability, conformality, and thickness control. The present study provides new fundamental insights regarding the vapor deposition of ZIF-8 from zinc oxide (ZnO). During synthesis, [...] Read more.

In recent years, the vapor deposition of zeolitic imidazolate framework-8 (ZIF-8) has gained high attraction due to its good scalability, conformality, and thickness control. The present study provides new fundamental insights regarding the vapor deposition of ZIF-8 from zinc oxide (ZnO). During synthesis, ZnO thin films with different percentages of open porosity (14.5%–24%) were subjected to a 2-methylimidazole vapor for different conversion times (20 min–24 h). For the first time, the impact of the porosity of ZnO thin films onto the converted ZIF-8 is investigated. Grazing incidence X-ray diffraction reveals randomly oriented crystallites of ZIF-8, which already appear after 20 min of conversion. The thickness, roughness, and average particle height of the ZIF-8 layers increase with the conversion time, reaching values up to (172 ± 20) nm, (29 ± 3) nm, and (113 ± 8) nm, respectively, for ZIF-8 obtained from ZnO with 14.5% open porosity. At long conversion times (i.e., 24 h), the results hint at greater precursor porosities resulting in lower thicknesses of ZIF-8, as the thickness, roughness, and average particle height for ZIF-8 obtained from 24%-porous ZnO show values of (132 ± 20) nm, (25 ± 3) nm and (80 ± 8) nm, respectively. Additionally, the potential of the ZIF-8 layers as a photocatalyst for the degradation of the organic dye methylene blue was studied. The ZIF-8 enhances the degradation by approximately 8% when compared to degradation without a photocatalyst. Full article

(This article belongs to the Special Issue Thin-Film Synthesis, Characterization and Properties)

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12 pages, 4488 KiB

Open AccessArticle

Corrosion and Wear Properties of Cr Coating and ZrO₂/Cr Bilayer Coating on Zr-4 Alloy

by Xiaolong Pan, Longshi Qiu, Xiaogang Hu and Haixia Jiang

Coatings 2022, 12(9), 1281; https://doi.org/10.3390/coatings12091281 - 01 Sep 2022

Cited by 7 | Viewed by 1443

Abstract

In this study, duplex surface treatments were used to prepare a ZrO₂/Cr bilayer coating on zirconium alloy cladding for enhancing the wear and corrosion behaviors. The surface and cross-section morphology of coated Zr-4 alloy was characterized; the results show that the [...] Read more.

In this study, duplex surface treatments were used to prepare a ZrO₂/Cr bilayer coating on zirconium alloy cladding for enhancing the wear and corrosion behaviors. The surface and cross-section morphology of coated Zr-4 alloy was characterized; the results show that the Cr- and ZrO₂/Cr-coated samples had similar morphology, and more obvious surface undulates could be observed on the ZrO₂/Cr coating than the pure Cr coating owing to the rough surface of the plasma electrolytic oxidation coating. Wear and electrochemical behavior in 1200 mg/L H₃BO₃ and 2.2 mg/L LiOH solutions of original and coated Zr-4 alloy were investigated. The electrochemical corrosion test indicated the coated Zr-4 alloy exhibited better corrosion resistance behavior than the original Zr-4 alloy. The potentiodynamic polarization curves and corrosion morphology suggest the pitting corrosion occurred on the surface of the original and coated Zr-4 alloy. The ZrO₂/Cr-coated Zr-4 alloy had better corrosion resistance due to the dual protection of the PEO layer and Cr coating. The wear behavior of the original and coated Zr-4 alloy was also investigated under a constant load of 5 N. The results reveal that the coated Zr-4 alloy had better wear resistance, and the PEO layer was found to significantly enhance the wear resistance of the Zr-4 alloy. Full article

(This article belongs to the Special Issue Thin-Film Synthesis, Characterization and Properties)

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18 pages, 4247 KiB

Open AccessArticle

Effect of Modified Tetraethyl Orthosilicate Surface Treatment Agents on the Permeability of Airport Pavement Concrete

by Tianlun Li and Yonggen Wu

Coatings 2022, 12(7), 1027; https://doi.org/10.3390/coatings12071027 - 20 Jul 2022

Viewed by 1531

Abstract

In this paper, three modified tetraethyl orthosilicate surface treatment agents were prepared by using tetraethyl orthosilicate (TEOS) as the preparation monomer, isobutyltriethoxysilane (IBTS) as the hybridizer, and acrylic acid, phosphoric acid, and hydrochloric acid as the catalysts. The effects of the three modified [...] Read more.

In this paper, three modified tetraethyl orthosilicate surface treatment agents were prepared by using tetraethyl orthosilicate (TEOS) as the preparation monomer, isobutyltriethoxysilane (IBTS) as the hybridizer, and acrylic acid, phosphoric acid, and hydrochloric acid as the catalysts. The effects of the three modified tetraethyl orthosilicate surface treatment agents on the permeability of airport pavement surface concrete were investigated by water absorption tests, water contact angle tests, water penetration resistance tests, chloride ion penetration resistance tests, and carbonation tests, and the mechanisms of action of the modified tetraethyl orthosilicate surface treatment agents were analyzed by microscopic tests. The results showed that all three tetraethyl orthosilicate surface treatment agents could significantly improve the impermeability of concrete, among which the modified tetraethyl orthosilicate surface treatment agent with hydrochloric acid as the catalyst had the most obvious effect on the improvement of the impermeability of concrete. Acrylic acid was weaker than hydrochloric acid as the catalyst of a modified tetraethyl orthosilicate surface treatment agent for the improvement of concrete impermeability; it was only slightly stronger than hydrochloric acid as the catalyst of modified tetraethyl orthosilicate surface treatment agent in terms of the improvement of concrete’s resistance to water penetration, and the difference between the two was not significant. Phosphoric acid as a catalyst of the modified tetraethyl orthosilicate surface treatment agent was the least effective for concrete impermeability; it was only stronger than the other two modified tetraethyl orthosilicate surface treatment agents in the improvement of concrete resistance to carbonation, and the carbonation depth of the concrete was only 1 mm in 28 days. SEM and MIP tests showed that the modified tetraethyl orthosilicate surface treatment agents improved the impermeability of concrete mainly by producing additional hydrated calcium silicate gel to plug microcracks and pores, reduce the total porosity of the concrete and the number of multi-harmful and harmful pores, and improve the compactness of the concrete. The test results can provide a reference for the development of modified tetraethyl orthosilicate surface treatment agents and their application in airport pavement surface engineering. Full article

(This article belongs to the Special Issue Thin-Film Synthesis, Characterization and Properties)

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18 pages, 2236 KiB

Open AccessEditor’s ChoiceArticle

Synthesis and Characterization of Boron Thin Films Using Chemical and Physical Vapor Depositions

by Bart Schurink, Wesley T. E. van den Beld, Roald M. Tiggelaar, Robbert W. E. van de Kruijs and Fred Bijkerk

Coatings 2022, 12(5), 685; https://doi.org/10.3390/coatings12050685 - 16 May 2022

Cited by 3 | Viewed by 2877

Abstract

Boron as thin film material is of relevance for use in modern micro- and nano-fabrication technology. In this research boron thin films are realized by a number of physical and chemical deposition methods, including magnetron sputtering, electron-beam evaporation, plasma enhanced chemical vapor deposition [...] Read more.

Boron as thin film material is of relevance for use in modern micro- and nano-fabrication technology. In this research boron thin films are realized by a number of physical and chemical deposition methods, including magnetron sputtering, electron-beam evaporation, plasma enhanced chemical vapor deposition (CVD), thermal/non-plasma CVD, remote plasma CVD and atmospheric pressure CVD. Various physical, mechanical and chemical characteristics of these boron thin films are investigated, i.e., deposition rate, uniformity, roughness, stress, composition, defectivity and chemical resistance. Boron films realized by plasma enhanced chemical vapor deposition (PECVD) are found to be inert for conventional wet chemical etchants and have the lowest amount of defects, which makes this the best candidate to be integrated into the micro-fabrication processes. By varying the deposition parameters in the PECVD process, the influences of plasma power, pressure and precursor inflow on the deposition rate and intrinsic stress are further explored. Utilization of PECVD boron films as hard mask for wet etching is demonstrated by means of patterning followed by selective structuring of the silicon substrate, which shows that PECVD boron thin films can be successfully applied for micro-fabrication. Full article

(This article belongs to the Special Issue Thin-Film Synthesis, Characterization and Properties)

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8 pages, 2393 KiB

Open AccessArticle

Enhanced Properties of Micro Arc Oxidation Coating with Cu Addition on TC4 Alloy in Marine Environment

by Wei Gao, Jiangnan Liu, Jingpeng Wei, Yuhong Yao, Xiqun Ma and Wei Yang

Coatings 2021, 11(10), 1168; https://doi.org/10.3390/coatings11101168 - 27 Sep 2021

Cited by 4 | Viewed by 1694

Abstract

By contrast with the traditional method of adding hard particles into micro arc oxidation (MAO) coating to improve its wear performance, this study introduced copper into the MAO coating on TC4 alloy by adding copper pyrophosphate to enhance the wear property in a [...] Read more.

By contrast with the traditional method of adding hard particles into micro arc oxidation (MAO) coating to improve its wear performance, this study introduced copper into the MAO coating on TC4 alloy by adding copper pyrophosphate to enhance the wear property in a marine environment and the antibacterial property. The results demonstrated that the MAO coating with copper pyrophosphate addition showed a porous structure, and Cu was mainly concentrated around micropores. CuO and Cu₂O were formed in this MAO coating. This MAO coating with Cu had a high bonding strength to the substrate. Although the hardness of the coating with Cu had been reduced, it could reduce the friction coefficient and enhance the wear property in simulated seawater due to the lubrication of Cu. Furthermore, this MAO coating with Cu addition had obvious antibacterial and bactericidal effects due to the antibacterial effect of Cu. Full article

(This article belongs to the Special Issue Thin-Film Synthesis, Characterization and Properties)

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12 pages, 18906 KiB

Open AccessArticle

Moisture-Assisted Formation of High-Quality Silver Nanowire Transparent Conductive Films with Low Junction Resistance

by Lipeng Zhou, Yuehui Hu, Hao Gao, Youliang Gao, Wenjun Zhu, Lilin Zhan, Huiwen Liu, Yichuan Chen, Keyan Hu, Pengfei Wang, Di Wang, Fang Hu, Ke Zhou, Wei Liu and Ning Chang

Coatings 2021, 11(6), 671; https://doi.org/10.3390/coatings11060671 - 01 Jun 2021

Cited by 6 | Viewed by 2737

Abstract

Silver nanowire (AgNWs) transparent conductive film (TCF) is considered to be the most favorable material to replace indium tin oxide (ITO) as the next-generation transparent conductive film. However, the disadvantages of AgNWs, such as easy oxidation and high wire-wire junction resistance, dramatically limit [...] Read more.

Silver nanowire (AgNWs) transparent conductive film (TCF) is considered to be the most favorable material to replace indium tin oxide (ITO) as the next-generation transparent conductive film. However, the disadvantages of AgNWs, such as easy oxidation and high wire-wire junction resistance, dramatically limit its commercial application. In this paper, moisture treatment was adopted, and water was dripped on the surface of AgNWs film or breathed on the surface so that the surface was covered with a layer of water vapor. The morphology of silver nanowire mesh nodes is complex, and the curvature is large. According to the capillary condensation theory, water molecules preferentially condense near the geometric surface with significant curvature. The capillary force is generated, making the wire-wire junction of AgNWs mesh bond tightly, resulting in good ohmic contact. The experimental results show that AgNWs-TCF treated by moisture has better conductivity, with an average sheet resistance of 20 Ω/sq and more uniform electrical properties. The bending test and adhesion test showed that AgNWs-TCF treated by moisture still exhibited good mechanical bending resistance and environmental stability. Full article

(This article belongs to the Special Issue Thin-Film Synthesis, Characterization and Properties)

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12 pages, 6080 KiB

Open AccessArticle

Two-Step Deposition of Silicon Oxide Films Using the Gas Phase Generation of Nanoparticles in the Chemical Vapor Deposition Process

by Jae-Ho Suk, Sung-Chun Hong, Gil-Su Jang and Nong-Moon Hwang

Coatings 2021, 11(3), 365; https://doi.org/10.3390/coatings11030365 - 23 Mar 2021

Cited by 2 | Viewed by 2091

Abstract

Non-classical crystallization, in which charged nanoparticles (NPs) are the building blocks of film growth, has been extensively studied in chemical vapor deposition (CVD). Here, the deposition behavior of silicon oxide films by the two-step growth process, where NPs are generated in the gas [...] Read more.

Non-classical crystallization, in which charged nanoparticles (NPs) are the building blocks of film growth, has been extensively studied in chemical vapor deposition (CVD). Here, the deposition behavior of silicon oxide films by the two-step growth process, where NPs are generated in the gas phase at high temperature and deposited as films at low temperature, was studied in the CVD process. Although we supplied SiH₄, H₂, and N₂, the deposited film turned out to be silicon oxide, which is attributed to relatively poor vacuum. Also, silicon oxide NPs were captured on transmission electron microscopy (TEM) carbon membranes of a copper grid for 10 s under various conditions. When the quartz tube with a conical nozzle was used, the size of nanoparticles increased drastically with increasing processing time (or delay time) and porous films with a rough surface were deposited. When the quartz tube without a nozzle was used, however, the size did not increase much with increasing processing time and dense films with a smooth surface were deposited. These results suggest that the size of nanoparticles is an important parameter for the deposition of dense films for two-step growth at low temperatures. Full article

(This article belongs to the Special Issue Thin-Film Synthesis, Characterization and Properties)

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18 pages, 21009 KiB

Open AccessArticle

Synthesis and Characterization of Nanostructured Polyaniline Thin Films with Superhydrophobic Properties

by Zeinab Abdel Hamid, Mona Hasan Gomaa, Sayed S. Abdel Rehim, Maamoun Abdel Hamid and Ahmed Ibrahim

Coatings 2019, 9(11), 748; https://doi.org/10.3390/coatings9110748 - 11 Nov 2019

Cited by 20 | Viewed by 4017

Abstract

Polyaniline (PANI) thin films incorporated with TiO₂ or ZnO nanoparticles were synthesized via an electrochemical polymerization technique. Cyclic voltammetry (CV) was used to synthesize PANI from a strongly acidic medium (0.5 M H₂SO₄). The effects of different deposition [...] Read more.

Polyaniline (PANI) thin films incorporated with TiO₂ or ZnO nanoparticles were synthesized via an electrochemical polymerization technique. Cyclic voltammetry (CV) was used to synthesize PANI from a strongly acidic medium (0.5 M H₂SO₄). The effects of different deposition cycles on the morphology, thickness, color, and properties of electrodeposited PANI thin films nanocomposites were investigated. Furthermore, the effects of the nanoparticles concentration on the morphology and water contact angle (CA) of the produced coating were investigated. Field-emission scanning electron microscopy (FE-SEM) and high-resolution transmission electron microscopy (HR-TEM) were used to investigate the morphological structure. X-ray photoelectron spectroscopy (XPS) was used to study the surface composition of the formed film. The results reveal that the CA of the prepared coating reached 146°. A granular morphology of PANI with a moderate concentration of nanoparticles was obtained. In addition, XPS analysis confirmed the incorporation of the oxide nanoparticles in the matrix. Full article

(This article belongs to the Special Issue Thin-Film Synthesis, Characterization and Properties)

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6 pages, 3277 KiB

Open AccessArticle

Fingerprint Blurring on a Hierarchical Nanoporous Layer Glass

by Erika Tabata, Takumi Ito, Yuki Ushioda and Takuya Fujima

Coatings 2019, 9(10), 653; https://doi.org/10.3390/coatings9100653 - 10 Oct 2019

Cited by 5 | Viewed by 2555

Abstract

A fingerprint blurring phenomenon on a hierarchical nanoporous layer (HNL) glass has been discovered and experimentally investigated. The HNL glass was prepared by a simple one-pot etching as reported by the authors. IR absorption spectra and water contact angle revealed that the blurring [...] Read more.

A fingerprint blurring phenomenon on a hierarchical nanoporous layer (HNL) glass has been discovered and experimentally investigated. The HNL glass was prepared by a simple one-pot etching as reported by the authors. IR absorption spectra and water contact angle revealed that the blurring does not come from a chemical decomposition but a transportation of the fingerprint components, and the capillary action drives the transportation, not the thermal diffusion. The fine pores in the HNL was indicated to develop the strong capillary force to blur the fingerprint. The fingerprint blurring phenomenon on the HNL can be a candidate for the third anti-fingerprint methodology after the popular ones of low frictional surfaces and anti-glare surfaces. Full article

(This article belongs to the Special Issue Thin-Film Synthesis, Characterization and Properties)

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