Resistivity Of Films Research Articles

Optimizing electrical resistivity in flexible conductive films via silver nanowire doping

Silver nanowires (AgNWs) have attracted significant research interest due to their potential in conductive films, flexible electronics, electromagnetic interference (EMI) shielding, sensors, energy storage, and integration into wearable devices. This study developed conductive inks with tailored viscosities for fabricating films with stable electrical resistance. The formulations were optimized for screen printing, inkjet printing, and direct writing by doping AgNWs into carbon paste dispersed in N,N-dimethylformamide (DMF). Flexible conductive circuits were printed on silk film substrates, and their electrical resistance was evaluated by varying AgNWs concentration and the number of printed layers. Cyclic bending and energizing heating experiments were conducted to assess durability. The results demonstrated that doping with AgNWs significantly reduced film resistivity, with a concentration of 30 mg/ml being optimal for screen-printing, inkjet, and direct printing. Screen-printed films exhibited the lowest resistivity, decreasing from 1.2 × 10-4 Ω·cm to 3.5 × 10-5 Ω·cm with increasing AgNWs concentration from 5 to 30 mg/ml. The resistivity of inkjet-printed and direct-written films at 30 mg/ml AgNWs was 5.8 × 10-5 Ω·cm and 7.2 × 10-5 Ω·cm, respectively. Increasing the number of printed layers from 1 to 7 further reduced resistivity by 62% for screen printing, 58% for inkjet printing, and 55% for direct writing. Cyclic bending tests showed that after 1000 bending cycles, the resistance increased by 18% for screen-printed films, 25% for inkjet-printed films, and 30% for direct-written films. Screen-printed films exhibited the lowest resistivity and longest service life, highlighting their potential for diverse applications in flexible electronics and the broader electronics industry.

Tailoring the Electrocatalytic Activity and Corrosion Resistance of CoCrFeNi and MnCrFeNi Thin Films by Anodization

AbstractTransition metal oxides like Co, Ni, and Mn are promising alternatives to noble metals such as Pt for oxygen electrocatalysis in green energy. Alloying these metals forms multicomponent catalysts with compelling properties. In this study, CoCrFeNi and MnCrFeNi thin films are synthesized using High‐Power Impulse Magnetron Sputtering (HiPIMS) and their catalytic activity for the Oxygen Reduction Reaction (ORR), the Oxygen Evolution Reaction (OER), and corrosion resistance in 1 molar (1 M) potassium hydroxide (KOH) are evaluated. MnCrFeNi films exhibit a fine‐grained single face‐centered cubic (FCC) phase, while CoCrFeNi films have larger grains and multiple phases. ORR on CoCrFeNi follows a 2+1 electron transfer pathway, producing hydroxide radicals, while MnCrFeNi exhibits a 2‐electron pathway, yielding hydrogen peroxide. Anodization reduces the CoCrFeNi overpotential from 0.9 to 0.5 V versus the reversible hydrogen electrode (RHE), comparable to platinum and iridium catalysts (Pt/C, Ir/C). Anodization also shifts CoCrFeNi ORR to a 2‐electron pathway. In situ Raman spectroscopy detects no ORR intermediates, but nickel oxyhydroxide (NiOOH) appears during OER. Substituting Mn for Co increases corrosion resistance by raising the corrosion potential. All films show passive behavior during polarization, demonstrating their potential for corrosion protection and electrocatalysis in green energy applications.

Stabilization of oxygen vacancy ordering and electrochemical-proton-insertion-and-extraction-induced large resistance modulation in strontium iron cobalt oxides Sr(Fe,Co)Oy

Electrochemically inserting and extracting hydrogen into and from solids are promising ways to explore materials’ phases and properties. However, it is still challenging to identify the structural factors that promote hydrogen insertion and extraction and to develop materials whose functional properties can be largely modulated by inserting and extracting hydrogen through solid-state reactions at room temperature. In this study, guided by theoretical calculations on the energies of oxygen reduction and hydrogen insertion reactions with oxygen-deficient perovskite oxides, we demonstrated that the oxygen vacancy ordering in Sr(Fe1−xCox)Oy (SFCO) epitaxial films can be stabilized by increasing the Co content (x ≥ 0.3) and revealed that it plays a key role in promoting proton accommodation into the SFCO lattice. We also show that the electrical resistance of SFCO films can be reversibly modulated by electrochemical proton insertion and extraction, and the modulation exceeds three orders of magnitude for Sr(Fe0.5Co0.5)O2.5 epitaxial films. Our results provide guidelines for controlling material properties through the insertion and extraction of hydrogen and for designing and exploring hydrogen-insertion materials.

The effect of Ta alloyed state on the corrosion resistance of TC4 surface laser cladding high entropy alloy

Ti4Al0.5NiCr2NbTa0.5 non-equimolar high entropy alloy (HEA) coatings were successfully prepared by laser cladding technology, the Ta element alloyed state in the coatings was changed by adjusting the laser energy density during cladding. The effects of Ta alloyed state on the phase structure, microstructure evolution, microhardness, corrosion resistance and passivation film of coatings were investigated. The results showed that the Ti4Al0.5NiCr2NbTa0.5 coating was composed of BCC and Ti2Ni-laves phases. With the increase in energy density, the increased content of Ta in the BCC phase promotes the formation of the BCC phase while suppressing the precipitation of the Ti₂Ni-Laves phase. However, this also leads to the transformation of the BCC phase from a fine dendritic structure to coarse equiaxed crystals. Meanwhile, the Laves phase, which is initially distributed in a reticulated at the grain boundaries, gradually fragments into a dotted distribution within the BCC phase. As grain coarsening occurs and the Laves phase decreases, the effects of fine-grain strengthening and second-phase strengthening gradually weaken, and the microhardness of the coating decreases from 675.5 HV to 483.4 HV. Additionally, the coating exhibited excellent corrosion resistance. With the change in the alloyed state of Ta, the stability of the passive film on the coating gradually increased, and the oxides of the refractory elements Ta and Nb transitioned from a sub-oxidized state to a stable oxidized state. The minimum corrosion current density of the coatings was only 0.877×10-8 A/cm2, and secondary passivation were observed during the polarization treatment of all coatings.

Evaluating the effect of Si and Mg addition on the corrosion performance of gravity-cast Al-12Ce alloys in NaCl solutions

The present investigation assesses the immersion and electrochemical corrosion performance of gravity-cast Al-12Ce and Al-12Ce-X alloys (X = 0.4Mg, 4.0Si, and 4.0Si+0.4Mg, all in wt.%) targeted for diesel engine applications in 0.1M and 3.5wt.% NaCl solutions for the first time. The findings revealed that the Al-12Ce-4Si alloy exhibited highest weight loss (+107%), while Al-12Ce-0.4Mg alloy illustrated the lowest weight loss (-26%) compared to Al-12Ce alloy in both solutions. With increasing exposure time from 0 to 168hours, the open circuit potential (OCP) of the alloys increases, being lower in 3.5wt.% NaCl compared to 0.1M NaCl. Among all the alloys, the Al-12Ce-0.4Mg alloy displayed the lowest double layer capacitance, highest charge transfer resistance, and highest film resistance in both NaCl solutions, indicating its superior corrosion resistance. The current density and electrochemical corrosion rates were the highest for Al-12Ce-4Si alloy and lowest for Al-12Ce-0.4Mg alloy, highlighting the highest corrosion resistance of Al-12Ce-0.4Mg alloy. Corrosion rates of all the alloys were higher in 3.5wt.% NaCl than in aqueous 0.1M NaCl. Cracking and pitting was most severe in Al-12Ce-4Si alloy and least in Al-12Ce-0.4Mg alloy. The α-Al phase adjacent to the CeAlSi2 phase in Al-12Ce-4Si alloy was highly corroded, while the α-Al phase adjacent to Al11Ce3 in Al-12Ce-0.4Mg alloy was less corroded.

Analyses of the Properties of the NiO-Doped Ga2O3 Wide-Bandgap Semiconductor Thin Films

The study began by pre-sintering Ga2O3 powder at 950 °C for 1 h, followed by the preparation of a mixture of Ga2O3 and 12 at% NiO powders to fabricate a source target material. An electron beam (e-beam) system was then used to deposit NiO-doped Ga2O3 thin films on Si substrates. X-ray diffraction (XRD) analyses revealed that the pre-sintered Ga2O3 at 950 °C exhibited β-phase characteristics, and the deposited NiO-doped Ga2O3 thin films exhibited an amorphous phase. After the deposition of the NiO-doped Ga2O3 thin films, they were divided into two portions. One portion underwent various analyses directly, while the other was annealed at 500 °C in air before being analyzed. Field-emission scanning electron microscopy (FESEM) was utilized to process the surface observation, and the cross-sectional observation was primarily used to measure the thickness of the NiO-doped Ga2O3 thin films. UV-Vis spectroscopy was used to calculate the bandgap by analyzing the transmission spectra, while the Agilent B1500A was employed to measure the I-V characteristics. Hall measurements were also performed to assess the mobility, carrier concentration, and resistivity of both NiO-doped Ga2O3 thin films. The first innovation is that the 500 °C-annealed NiO-doped Ga2O3 thin films exhibited a larger bandgap and better electrical conductivity. The manuscript provides an explanation for the observed increase in the bandgap. Another important innovation is that the 500 °C-annealed NiO-doped Ga2O3 thin films revealed a high-energy bandgap of 4.402 eV. The third innovation is that X-ray photoelectron spectroscopy (XPS) analyses of the Ga2p3/2, Ga2p1/2, Ga3d, Ni2p3/2, and O1s peaks were conducted to further investigate the reasons behind the enhanced electrical conductivity of the 500 °C-annealed NiO-doped Ga2O3 thin films.

Preparation and characterization of trivalent chromium conversion films containing Cr(NO3)3 and Co(NO3)2 on Zn-Ni electroplated films of 2024 aluminum alloy substrates

Purpose The purpose of this study is to prepare trivalent chromium conversion (TCC) film on the Zn-Ni electrodeposited film on the surface of 2024 aluminum alloy and to ensure that the TCC film has good corrosion resistance and electrical conductivity. Design/methodology/approach The morphology of the TCC film was studied by scanning electron microscopy, and the elemental composition of the TCC film was characterized by X-ray energy dispersive spectroscopy. The TCC film was tested and the roughness was analyzed by 3D morphology (white light interference). The electrochemical behavior and corrosion resistance of TCC films were studied by the Tafel polarization curve and electrochemical impedance spectroscopy, and the conductivity was tested. Findings The TCC films were uniformly black and bright in appearance and were mainly compounds of Zn, Ni and Cr with O. The electrochemical impedance of the TCC film is larger than that of the Zn-Ni film, the corrosion current (Icorr) is smaller than that of the Zn-Ni film and the corrosion potential (Ecorr) is larger than that of the Zn-Ni film, which has excellent corrosion resistance. TCCs were performed on the appropriate size of the shell sample, and the resistance of the shells was 1.5 mVDC, which meets the total resistance requirements of the test standard for composite connector accessories. Originality/value In this study, TCC film was successfully prepared on the Zn-Ni coating on the surface of 2024 aluminum alloy. The TCC film has good corrosion resistance and electrical conductivity.

The effect of addition sodium iodide on the thermal properties of (PEO) thin film

In this study, the thermal properties of polyethylene (PEO) thin films dispersed with a fixed amount of dopants of sodium iodide 0.1% by weight (0.1% wt.) were investigated. The thermal conductivity and thermal resistivity of pure PEO thin films and the prepared ones doped with sodium iodide composites have been studied at different temperatures. It was found that the thermal conductivity of these films increases with the increase in temperature and with the ones that doped with 0.1% sodium iodide.

Wafer-Level Packaging of Microelectromechanical Systems Based on Frame Structure

Modern microelectromechanical systems (MEMS) are devices that incorporate microelectronic components and micromechanical structures on a single chip. Packaging is a mandatory stage in MEMS manufacturing. It ensures mechanical protection, sealing and transmission of electric energy and signals. The present work was aimed at developing a MEMS packaging method as a part of the consolidated manufacturing process. The method is developed on the example of a microwave MEMS switch. The switch manufacturing scheme includes conventional technologies used for producing gallium arsenide integrated circuits: optical lithography, liquid etching, electron-beam and magnetron deposition of metallic, resistive and dielectric films. The work presents a new inter-plate MEMS packaging based on a frame structure with a passivating film. The main purpose of the package frame layer is mechanical support for an upper layer of the sealing material. The frame layer should have the structure allowing for unimpeded removal of the sacrificial photoresist and be impermeable for the sealant. To satisfy the requirements stated, a metallic thin copper-film spatial frame was fabricated by galvanic deposition. The frame structure is a geodesic dome comprised of a complex network of triangle cells arranged in rows. The connected triangles create a self-supporting durable framework. The measurement and modeling results demonstrate that the round frame structure is more durable than a square frame with the same maximum cell dimensions. The stress-strain state for the round framework considerably alters depending on the number of rows of triangle cells. In addition to the mechanical support, the cell structure of the framework – with adequate selection of cell dimensions, solvent and sealant viscosities – allows for unimpeded penetration of the solvent (N-methyl-2-pyrrolidone, NMP) and removal of ma-P1225 photoresist sacrificial layers. At the same time, the layer structure is impermeable for the sealant (benzocyclobutene, BCB). The proposed MEMS switch packaging enables mass fabrication of GaAs integrated circuits in a single process, which expands their frequency range. The new plate-level packaging technology is absolutely compatible with MEMS fabrication technology without specific materials and equipment which reduces the dimensions and cost of MEMS.

Wearable Resistive-Type Stretchable Strain Sensors: Materials and Applications.

The rapid advancement of wearable electronics over recent decades has led to the development of stretchable strain sensors, which are essential for accurately detecting and monitoring mechanical deformations. These sensors have widespread applications, including movement detection, structural health monitoring, and human-machine interfaces. Resistive-type sensors have gained significant attention due to their simple design, ease of fabrication, and adaptability to different materials. Their performance, evaluated by metrics like stretchability and sensitivity, is influenced by the choice of strain-sensitive materials. This review offers a comprehensive comparison and evaluation of different materials used in resistive strain sensors, including metal and semiconductor films, low-dimensional materials, intrinsically conductive polymers, and gels. The review also highlights the latest applications of resistive strain sensors in motion detection, healthcare monitoring, and human-machine interfaces by examining device physics and material characteristics. This comparative analysis aims to support the selection, application, and development of resistive strain sensors tailored to specific applications.

`Evaluation of the antimicrobial corrosion properties of electropolymerized poly(aniline-co-o-toluidine) films on carbon steel surfaces

Microbiologically influenced corrosion (MIC) can lead to structural weakening and shortened service life of carbon steel, resulting in serious economic losses and safety hazards. In particular, sulfate-reducing bacteria (SRB) produce hydrogen sulfide and sulfide during their growth and metabolism, which accelerates the corrosion of carbon steel. Thin films of poly(aniline-co-o-toluidine) (PA-co-POT) were electrodeposited on the surface of carbon steel using cyclic voltammetry in an electrolyte consisting of oxalic acid, aniline and o-toluidine monomers. The mechanical properties of the polymer films were analyzed by a micro-Vickers hardness tester. The corrosion resistance of the polymer films was evaluated by an electrochemical corrosion test and immersion test of the polymer films in a solution containing SRB and 3.5% NaCl. The results showed that PA-co-POT films have superior SRB corrosion resistance than single polymer films. The corrosion rate of PA-co-POT film was 0.0171mm/year, and the protection efficiency was 83% after 14 days of immersion in solution. In addition, due to the antibacterial properties of the PA-co-POT film, the adhesion of bacteria on its surface is significantly reduced, and local corrosion is also effectively inhibited. This study demonstrates the potential of electropolymerized aniline derivative copolymer films in preventing MIC of carbon steel and provides valuable insights for the development of new corrosion protection materials.

A Study on NbN Thin Films as Resistive Films Prepared via Reactive Magnetron Sputtering

The NbN thin films were deposited onto glass and Al2O3 substrates using reactive magnetron sputtering, employing a niobium target sputtered with a mixture of Ar and N2 gases. The investigation focused on the phase structures, microstructures, and electrical properties of the NbN thin films under various deposition powers and annealing temperatures. The results indicated the presence of a face-centered cubic (FCC) crystal structure in the as-deposited films at a power of 125 W. Interestingly, the crystallization phase remained unchanged within an annealing temperature range from room temperature to 500 °C. It was observed that the resistivity of the NbN thin films increased with higher nitrogen content, while the temperature coefficient of resistance (TCR) showed a tendency towards more negative values as the nitrogen content rose. Notably, at a nitrogen content of 9%, the film exhibited the lowest resistivity of 273 μΩ-cm with a TCR of -240 ppm/°C.

Synergistic analysis of oxygen transport resistance in polymer electrolyte membrane fuel cells

The oxygen transport resistance of polymer electrolyte membrane fuel cells operated under various conditions (e.g., temperature and relative humidity) was separated into molecular diffusion, Knudsen diffusion, and ionomer film (IF) resistances using the catalyst agglomerate model, dissection of oxygen transport resistance, and distribution of relaxation time analysis. Simultaneously, an analysis of resistance, including charge transfer, proton transfer, and high-frequency resistances, was performed. The Knudsen diffusion resistance of the catalyst layer was calculated by assessing the effects of relative humidity on porosity and pore size. Oxygen transport resistance was analyzed to establish a correlation between temperature, relative humidity, and IF resistance. Water negligibly impacted performance at low oxygen levels at all examined current densities. The fractional contributions of molecular diffusion, Knudsen diffusion, and IF resistances obtained using oxygen transport analysis could be effectively applied to mass transport resistance in the distribution of relaxation time analysis. The IF resistance in the catalyst layer was up to eight times higher than the Knudsen diffusion resistance and 150 times higher than the proton transfer resistance across all current densities, thus most strongly contributing to the catalyst layer resistance. In the gas diffusion layer, the molecular diffusion resistance was up to four times higher than the Knudsen diffusion resistance. Thus, we examined the relationship between the mass transport resistances of individual elements and IF behavior under different operating conditions, revealing that the design of the IF in the catalyst should be considered alongside the relationship between the gas diffusion layer and membrane for optimal performance.

Digital light processing printed resin based conductive composites with CF@Ag and HGMs@Ag as fillers for metamaterial absorbers

AbstractAn integrated fabrication process based on multi‐material Digital Light Processing (DLP) technique for metamaterial absorbers (MMAs) is proposed. Considering the requirements of the DLP process for the rheological properties and photocuring properties of the slurry, a photopolymer resin slurry was developed using silver‐plated carbon fiber (CF@Ag) and silver‐plated hollow glass microspheres (HGMs@Ag) as conductive fillers. To meet the conductivity requirements of resistive films in MMAs, the study systematically investigated the influence of material parameters and DLP process parameters on the conductivity and precision of the fabricated patterns. Optimized DLP parameters for isotropic photocurable conductive composites with high conductivity and low percolation thresholds were obtained. Additionally, a MMAs was designed to achieve effective absorption in the wavelength range of 7 to 28 GHz. The absorber utilized a resistive film with a thickness of 30 μm and an average surface resistivity of 23 ohm/sq., prepared using a photocurable resin filled with a total mass fraction of 35 wt% CF@Ag and HGMs@Ag in a 2:1 mass ratio. This work shows that it is feasible to fabricate resistive film patterns with prescribed surface resistivity and geometric shapes through DLP printing directly without sintering, providing a promising process for the integrated manufacturing of high‐performance MMAs.Highlights Developed a conductive slurry using the synergy between CF@Ag and HGMs@Ag. Proposed the preparation process of resistance controllable resistive film. The first demonstration of manufacturing resistive film‐type MMAs via DLP.

Unveiling the Effect of Ti Micro-Alloying on the Microstructure and Corrosion Resistance of the GH3536 Alloy Processed by Laser Metal Deposition in a Simulated Environment for PEMFCs.

This article addresses the knowledge gap regarding the effect of Ti addition on the microstructure and corrosion behavior of the LMD-processed GH3536 alloy in a simulated solution of proton exchange membrane fuel cells (PEMFCs). The microstructural evolution, corrosion resistance, and passive film characteristics of LMD-processed GH3536 alloy with varying Ti contents were characterized through a variety of techniques, including scanning electron microscopy (SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), electron backscatter diffraction (EBSD), X-ray photoelectron spectroscopy (XPS), and a series of electrochemical measurements. The results indicate that the corrosion resistance of the LMD-processed GH3536 alloy significantly improves with increasing Ti content. However, when the Ti content exceeds 0.2 wt.%, the beneficial effect on corrosion resistance is weakened. Two primary mechanisms explain the enhanced corrosion resistance, involving the heterogeneous nucleation of Ti-modified Al2O3 and Ti solute segregation, which promotes grain refinement. In addition, grain refinement can provide more active sites for the formation of compact passive films, thereby improving corrosion resistance of the GH3536 alloy.

Brick-cement system inspired fabrication of Ti3C2 MXene nanosheet reinforced high-performance of chitosan/gelatin/PVA composite films

The increasing need for convenient, fast, and nutritious of prepared foods elevate the development of biodegradable antibacterial packaging materials with excellent performance. Inspired by the brick-cement-like system, the two-dimensional nanomaterial Ti3C2 MXene as nanofillers with optothermal response function was employed to strength the performance of chitosan/gelatin/polyvinyl alcohol composite films (CGPF-Mxs). The results revealed that the high-modulus Ti3C2 MXene material improved the microstructures density of macromolecule polymers by physical interactions, as well as enhancements in mechanical properties, thermal stability, barrier properties, water resistance, and antioxidation performance of the composite films. The composite film with 0.75 % Ti3C2 MXene demonstrated the optimal performance. Additionally, the composite films exhibited efficient photothermal effect, which showed inhibition rate of 98.53 % for Staphylococcus aureus and 82.91 % for Escherichia coli under near-infrared laser. The proposed film revealed a potential application as packaging material for maintaining the quality of cooked meat products.

Multi-scale investigation of stainless-steel passivation in seawater concrete pore solution

Stainless-steel bars can be effectively used in seawater sea sand concrete due to their excellent resistance to chloride ions, contributing to resource conservation and sustainable development. However, the underlying impact mechanism of chloride ion on the passivation of stainless steel in seawater sea sand concrete has not been thoroughly studied. In this work, a multi-scale study was carried out to reveal the role of chloride ion on the passivation of stainless-steel bar in concrete. At the macro level, the presence of chloride ions reduced the corrosion resistance of the stainless-steel passive film, but did not cause corrosion. On the micro level, chloride ion interfered with the phase transformation of the passive film, increased Cr oxides and decreased the loose Fe3 + oxides. From the atomic view of point, the incorporation of chloride into the passive film was mainly due to the higher adsorption energy of Fe2O3 and Cr2O3 with chloride ion, increasing the reactivity of passive film. The presence of Mo in the outer layer of passive film presented a much lower adsorption energy of chloride compared with Fe2O3 and Cr2O3, impeding the ingress of chloride ion in the inner layer. Density functional theory (DFT) calculation complimented the knowledge of interaction of chloride ion with the passive film.

The crucial influence of Al on the high-temperature oxidation resistance of Ti1-xAlxBy diboride thin films (0.36 ≤ x ≤ 0.74, 1.83 ≤ y ≤ 2.03)

The crucial influence of Al on the high-temperature oxidation resistance of Ti1-xAlxBy diboride thin films (0.36 ≤ x ≤ 0.74, 1.83 ≤ y ≤ 2.03)

Enhanced solar-driven interfacial evaporation using composite hydrogel and nano filter films for sustainable water transport and salt resistance

Enhanced solar-driven interfacial evaporation using composite hydrogel and nano filter films for sustainable water transport and salt resistance

Broad-Passband Rasorber With Ultrawideband Absorption Incorporating Graphene-Based Resistive Films and Via-Based Winding Inductors

Broad-Passband Rasorber With Ultrawideband Absorption Incorporating Graphene-Based Resistive Films and Via-Based Winding Inductors