Magnetron Co-sputtering Method Research Articles

The enhancement in microstructure, optical and electromagnetic shielding properties of Al-doped Ag thin films by annealing treatment

Ag thin films having attractive optical transmittance and effective shielding capability are usually used as a preferred choice for the transparent electromagnetic shielding windows. Whereas, the Ag films are grown primarily via an island growth (Volmer-Weber) mechanism, which greatly restricts its application. In this study, by introducing Al atoms and suitable annealing treatment, the continuous and smooth Ag thin films are successfully fabricated by magnetron co-sputtering method. The effect of annealing temperature on the microstructure, optical and electromagnetic shielding properties of the films are conducted the comprehensive and profound study. Our results indicate that the 5 mol% Al-Ag thin film annealed at 200 °C could transform into planar growth structure, and display excellent the highest optical transmittance 89.15% at 550 nm. Meanwhile, the shielding effectiveness (SE) reaches a peak value of 28.1 dB. 500°C is estimated as the threshold annealing temperature of Al-Ag thin film with comprehensive performances gradually declining. Moreover, the Al dopants significantly improve the thermal stability of Ag thin films than that of the pure Ag films. These findings are of important guidance for the preparation of high-quality Al-Ag thin films to meet the practical applications.

Palladium enhanced electrochemical supercapacitive performance of chromium oxide thin films synthesized by sputtering process

Recently, the use of transition metal oxide electrodes for supercapacitor applications has increased due to the possibility of variable mixed valence states. The present study has established the use of Pd-Cr2O3 composite thin films as a working electrode for high-performance supercapacitors. The reactive dc magnetron co-sputtering method has been used for the fabrication of thin film of Cr2O3 and Pd-Cr2O3 on SS-304 substrate. X-ray diffraction and X-ray photoemission spectroscopy techniques were used to examine the surface chemistry and phase purity of chromium oxide and Pd-Cr2O3 composite thin films. The incorporation of Pd in Cr2O3 delivers a drastic change in the surface morphology. Due to the modified morphology and electronic properties, a noticeable improvement in the electrochemical properties of Pd-Cr2O3 electrode is observed. The obtained value of specific capacitance for this electrode is 401 Fg−1 at 0.1 mAcm−2 scan rate and within the potential window range 0 to +1.2 V. This value of specific capacitance is almost twice in comparison to the Cr2O3 based electrode. The Pd-Cr2O3 composite thin film shows a good cycle retention capability of 8000 cycles with 87.5 % retention. The obtained value of energy density and power density for Pd-Cr2O3 electrode was 80.2 Whkg−1 and 3.23 kWkg−1, respectively at 0.1 mAcm−2. Consequently, this composite material electrode can be seen as a promising advancement for electrodes in supercapacitor devices.

Study on the microstructure, optical performance, and electromagnetic shielding effectiveness of Al-Ag thin films for variable annealing time

Herein, the magnetron co-sputtering method is employed to fabricate 9 nm 5 mol% Al-Ag thin films, and subsequently annealing treatment is performed. The effect of the annealing time on the structure, optical, and electromagnetic (EM) shielding performance of them is thoroughly studied. It is observed that by subjecting the films to the appropriate annealing time, the Ag granules undergo a transformation into a planar growth structure and make the integrated performance of Al-Ag thin film more exceptional. Compared with other annealing time, when it is 5 min, the obtained Al-Ag thin films display the homogenous and smooth surface morphology. Moreover, it exhibits excellent optical properties with the highest transmittance value of 89.6% at 550 nm, and meanwhile the shielding effectiveness reaches a peak value of 28.7 dB. These characteristics render the Al-Ag thin films highly practical and valuable for EM shielding windows with high transmittance.

Sputtering pressure dependence of microstructure and magnetoresistance properties of non-uniform Co–ZnO nanocomposite film

Co-ZnO metal–semiconductor nanocomposite films have become the focus of attention in recent years since their magnetoresistance (MR) effect at room temperature (RT). In this study, non-uniform Co-ZnO nanocomposite films were prepared by magnetron co-sputtering method. With sputtering pressure increasing, the formation of ferromagnetic Co clusters is suppressed effectively, and the metallic-state superparamagnetic Co particles are dispersed, which form the tunneling transport paths in the Co-ZnO films at high Co content. As the sputtering pressure increases from 0.3 Pa to 1.2 Pa, the RT -MR value of the films increases from 0.41 % to 11.85 %, and the saturation magnetization of the films rises from 6.3 kGs to 7.3 kGs and then decreases to 6.7 kGs. It is noteworthy that the low-field MR field sensitivity at 1000 Oe is enhanced by about 10 times from 0.5 Pa to 1.2 Pa. This provides a reference for the application of low-magnetic field detectors.

Magnetron sputtering method for the preparation of Cu-ZrB2 composite film and their optical properties

The exceptional thermal and chemical stability of zirconium diboride (ZrB2) is attributed to its unique combination of ceramic and metallic properties. In this work, copper composited zirconium diboride (Cu-ZrB2) composite film was prepared on Si (100) substrates with dual-target magnetron co-sputtering method. The introduction of metal (Cu) has been observed to adjust the free electron concentration in thin films, thereby optimizing their properties. When copper was sputtered at 3 W, the composite film exhibited superior performance, demonstrating the average reflectance of 90% within the wavelength range of 3–14 μm. Additionally, it showcased remarkably low infrared emissivity values at 3–5 and 8–14 μm, measuring 0.309 and 0.294 respectively. This experiment has demonstrated that ZrB2-based composite films have great potentials in low infrared emissivity applications.

Analysis of the Effect of Copper Doping on the Optoelectronic Properties of Indium Oxide Thin Films and the Thermoelectric Properties of an In2O3/Pt Thermocouple

The detection and real-time monitoring of temperature parameters are important, and indium oxide-based thin film thermocouples can be integrated on the surface of heaters because they operate normally under harsh conditions and provide accurate online temperature monitoring. The higher stability and appropriate optical and electrical properties of In2O3 make it very suitable as an electrode material for thermocouple sensors. This work demonstrates that copper doping can alter the optical and electrical properties of In2O3 films and regulate the output performance of thermocouples. Copper-doped In2O3 thin films were prepared using the magnetron co-sputtering method. The doping concentration of Cu was controlled using direct current (DC) power. An In2O3/Pt thermocouple sensor was prepared, and the optoelectronic and thermocouple properties were adjusted by changing the copper doping content. The thickness valve of the thin film sample was 300 nm. The results of the X-ray diffraction suggested that the structure of the doped In2O3 thin films was cubic. The results of the energy-dispersive X-ray analysis revealed that Cu was doped into the In2O3 thin films. All deposited films were n-type semiconductor materials according to Hall effect testing. The 4.09 at% Cu-doped thin films possessed the highest resistivity (30.2 × 10−3 Ω·cm), a larger carrier concentration (3.72 × 1020 cm−3), and the lowest carrier mobility (0.56 cm2V−1s−1). The optical band gap decreased from 3.76 to 2.71 eV with an increase in the doping concentration, and the transmittance of the film significantly reduced. When the DC power was increased, the variation range of Seebeck coefficient for the In2O3/Pt thermocouple was 152.1–170.5 μV/°C, and the range of thermal output value was 91.4–102.4 mV.

Influence of substrate temperature on the properties of ZnTe:Cu films prepared by a magnetron co-sputtering method

Copper-doped Zinc Tellurium (ZnTe:Cu) films were deposited on borosilicate glass using magnetron co-sputtering technique. The influence of the substrate temperature on the structural, morphological, optical and electrical properties of ZnTe:Cu films was investigated by X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), UV–Vis spectrophotometer and Hall effect measurement system. The results indicate that substrate temperature significantly affects the properties of the ZnTe:Cu films. When the substrate temperature increases from room temperature to 600 °C, the (111)-preferred orientation of ZnTe:Cu films is gradually replaced by the (220)-preferred orientation. At high substrate temperatures (≥500 °C), the CuxTe phase appears in the ZnTe:Cu films, resulting in higher carrier concentration (>1019 cm−3) and lower resistivity (<10−2 Ω cm) of the prepared films.

Preparation and Characterization of Low- emissivity AlN/Ag/AlN Films by Magnetron Cosputtering Method

AlN and Ag thin films were deposited independently on the Si(100) wafers and glass slides by sputtering techniqueat various times to find the optimum deposition times for coating AlN and Ag films layers. The results obtained fromglazing-incident X-ray diffraction (GIXRD), field-emission scanning electron microscopy (FE-SEM), and transmittancemeasurements showed that the optimum deposition time for coating AlN and Ag film layers were 40 min and 15 scorresponding to the film thickness of 46.7 and 19.6 nm, respectively. The optimum deposition times were used forcoating AlN and Ag films in the multilayer AlN/Ag/AlN film stack. Then, the multilayer AlN/Ag/AlN film stack wasdeposited on the glass slide for transmittance measurement and a test glass plate with a size of 10 cm x 10 cm for infraredprotection testing. The average solar transmittances in the visible range ( = 380-780 nm) and in the near infrared range( = 780-2,000 nm) were found to be 48.05 and 15.17%, respectively which are comparable with those of a commercialglass.

Role of Cu-doping concentration in the synthesis, microstructure and properties of Ag thin films via magnetron co-sputtering method

The outstanding optical property and shielding effectiveness of the ultra-thin Ag films make them ideal for use as windows in various applications, such as TV-guided missiles, laser-guided missiles, and shielded cabin. The magnetron co-sputtering method was utilized for depositing ultra-thin Ag films (10 nm) on SiO2 substrates, and their properties were improved by introducing Cu dopants. The influence of Cu concentrations on the structure, optical and shielding performance was analyzed extensively. The study revealed that the addition of a few Cu could inhibit the growth of Ag particles in 3D-island mode, thereby facilitating their nucleation and continuous growth in the plane. The 10 nm Cu-doped Ag thin films by preparing with a Cu doping concentration of 2 mol%, displayed a uniform, continuous and smooth surface morphology whose root-mean-square (RMS) roughness is only 0.88 nm. Furthermore, the films demonstrated excellent optical property with a maximum transmittance of about 79.7% in the visible region. The highest shielding effectiveness (SE) at an optimal concentration of 2 mol% can reach peak value of 36.8 dB. These exceptional properties make Cu-doped Ag films highly valuable and applicable for electromagnetic shielding in transparent windows.

Reset-First and Multibit-Level Resistive-Switching Behavior of Lanthanum Nickel Oxide (LaNiO3-x) Thin Films.

The resistive random-access memory (RRAM) with multi-level storage capability has been considered one of the most promising emerging devices to mimic synaptic behavior and accelerate analog computations. In this study, we investigated the reset-first bipolar resistive switching (RS) and multi-level characteristics of a LaNiO3-x thin film deposited using a reactive magnetron co-sputtering method. Polycrystalline phases of LaNiO3 (LNO), without La2O3 and NiO phases, were observed at similar fractions of Ni and La at a constant partial pressure of oxygen. The relative chemical proportions of Ni3+ and Ni2+ ions in LaNiO3-x indicated that it was an oxygen-deficient LaNiO3-x thin film, exhibiting RS behavior, compared to LNO without Ni2+ ions. The TiN/LaNiO3-x/Pt devices exhibited gradual resistance changes under various DC/AC voltage sweeps and consecutive pulse modes. The nonlinearity values of the conductance, measured via constant-pulse programming, were 0.15 for potentiation and 0.35 for depression, indicating the potential of the as-fabricated devices as analog computing devices. The LaNiO3-x-based device could reach multi-level states without an electroforming step and is a promising candidate for state-of-the-art RS memory and synaptic devices for neuromorphic computing.

Ti-doping inducing high-performance flexible p-type Bi0.5Sb1.5Te3-based thin film

Bi2Te3-based flexible thermoelectric power generator is a competitive candidate for wearable electronics. However, the strongly coupled Seebeck coefficient and electrical conductivity limits thermoelectric performance of p-type Bi0.5Sb1.5Te3-based flexible thin films (f-TFs). In this work, we report Ti-doping by a magnetron co-sputtering method can strengthen the texture orientation of as-prepared Bi0.5Sb1.5Te3-based f-TFs and correspondingly contribute to a high electrical conductivity of 532.69 S cm−1 at room temperature. Under simultaneously optimized carrier concentration (nh), a high Seebeck coefficient of ∼196.15 μV K−1 and an high room-temperature power factor of ∼19.67 μW cm−1 K−2 have been achieved. A 3 single-leg flexible thermoelectric device demonstrates high applicability. Simultaneously, the as-prepared Ti-doped Bi0.5Sb1.5Te3 f-TFs and device demonstrate high bending resistance as evidenced by the <10% change of thermoelectric performance before and after bending. Our study indicates that Ti-doping can simultaneously tune the texture orientation and nh of Bi0.5Sb1.5Te3-based f-TFs and achieve high thermoelectric performance.

Structural, Optical, and Dielectric Properties of Ion-Conducting LiAlO2 Thin Films Produced by Reactive Magnetron Co-sputtering

This study reports on the properties of LiAlO2 thin films compared to Al2O3 and Li2O thin films, considering their application as an ion-conducting dielectric in metal–insulator–metal (MIM) capacitors. The reactive magnetron co-sputtering method for the deposition of LiAlO2 is presented for the first time. This room-temperature method dedicates an amorphous LiAlO2 film with a smooth surface (Rrms ∼ 0.34 nm) and uniform morphology, which was determined by X-ray diffraction (XRD), atomic force microscopy (AFM), and scanning electron microscopy (SEM) techniques. UV–vis spectroscopy points to the formation of LiAlO2 with high transparency and a wide band gap. The fabricated MIM capacitors were analyzed using impedance spectroscopy to determine the cross-plane conductivity and dielectric properties. Incorporation of lithium ions into the alumina results in an ionic conduction mechanism with a room-temperature conductivity of 2.23 × 10–11 S cm–1 and activation energy of 0.69 eV consistent with the Arrhenius relation. The capacitance–frequency study for LiAlO2-based capacitors shows a stabilized behavior with a capacitance of 123.51 nF/cm2. The enhancement in the dielectric constant (k ∼ 25.76) coupled with a high band gap energy (Eg ∼ 5.49 eV) is determined. These results suggest the production of thin film capacitors with better energy storage performance and lower loss by using an ion-conducting dielectric.

Effects of Al-doping concentration on the structure and electromagnetic shielding properties of transparent Ag thin films

The ultra-thin Ag films with fascinating optical properties and shielding performance have broad applications in the fields of solar cells, transparent electrodes, optical spectrum filters, low-emissivity coatings, transparent electromagnetic shielding windows, etc. In this work, by introducing Al dopant, ultra-thin Ag transparent films were successfully prepared on quartz glass substrates using magnetron co-sputtering method. Effects of the Al-doping concentration on the structure, transmittance and electromagnetic shielding properties of Ag thin films were investigated in detail. It was found that a certain amount of Al can suppress the 3D island growth of Ag granules, and thus promote nucleation and continuous in plane growth. At the Al doped concentration of 5 mol%, the prepared 9 nm Al doped Ag thin films exhibited continuous, uniform and smooth surface morphology with the RMS roughness of only 0.89 nm. Meanwhile, it has good optical property with the highest transmittance value of 80.2% in the visible range and 76.8% at 550 nm. As the increase of Al concentration, the shielding effectiveness of the films goes up and then down, and the optimum concentration for maximum shielding effectiveness (SE) is about 5 mol% at which the maximum SE can reach up to 34.5 dB. These features make the Al-doped Ag thin films very useful and practical for transparent electromagnetic shielding window.

High-entropy alloy nitride nanofilms via a co-sputtering method enable superior optical performance and thermal robustness

• HEN (ZrNbMo-Al-N) films are prepared through a reactive magnetron co-sputtering method. • A tri-layer SSA is fabricated based on HEN (ZrNbMo-Al-N) films. • The absorbers on Cu substrates show high absorptance (96.2%) and low emittance (6.6%). • The absorbers on SS Substrates exhibit superior thermal robustness at 400 °C. High-entropy ceramics are a new class of solar-thermal material with high configurational entropy, lattice distortion, and flexible component space. In this work, we report a tri-layer solar selective absorber based on high-entropy nitride (ZrNbMo-Al-N), which can be deposited on various substrates through reactive magnetron co-sputtering. The absorbers on Cu substrates exhibit a remarkable solar absorptivity of 96.2% and a suppressed thermal emissivity of 6.6%. Moreover, the absorbers on stainless steel (SS) substrates show superior thermal robustness. After annealing at 400 °C for 168 h in a vacuum condition, they retain a high absorptivity of 94.4% and a low thermal emissivity of 9.8%.

Ultra-strong Mg alloy with nano-grain structures produced by a high-throughput magnetron co-sputtering method for the full chemistry spectra

Ultra-strong Mg alloy with nano-grain structures produced by a high-throughput magnetron co-sputtering method for the full chemistry spectra

Growth of High-Quality Perovskite KTa1-xNbxO3 Thin Films by RF Magnetron Co-Sputtering

In this study, we demonstrate the growth of high-quality KTa1-xNbxO3 (KTN) thin films by using multi-target radio frequency (RF) magnetron co-sputtering with KTaO3, KNbO3, and K2CO3 targets. KTaO3 and KNbO3 targets were used to control the Ta/Nb ratio while the K2CO3 target was used to supply excess potassium (K) to compensate for the K deficiency. Through careful control of the RF powers applied to each target, high-quality perovskite KTN (x = 0.53) thin films were grown on various single crystal substrates. Variable temperature Raman spectroscopy revealed that the KTN thin films exhibit a ferroelectric phase at room temperature with a Curie temperature of ~403 K. The optical constants n and k of the KTN thin film were also similar to those reported for single KTN crystals. These results present a simple route toward fabricating high-quality perovskite KTN thin films with desired structural and optical properties for various device applications utilizing the RF magnetron co-sputtering method.

Multifunctional Ag-ZrB2 composite film with low infrared emissivity, low visible light reflectance and hydrophobicity

Zirconium Boride (ZrB2) thin film exhibits excellent low infrared emissivity property, but the infrared emissivity in the mid-infrared waveband is still higher than that of traditional metal film. In this work, we reported Ag -ZrB2 nanocomposite film with low emissivity in the mid-infrared waveband by magnetron co-sputtering method. The effect of Ag content on properties of Ag-ZrB2 nanocomposite film were discussed in details. As the increase of Ag content, the infrared emissivity ε3-5μm and ε8-14μm decrease to 0.11 and 0.04 respectively. In addition, the reflectivity(R = 65%) of visible light is still lower than that of conventional metals. Consequently, the Ag-ZrB2 nanocomposite film shows low detectability in the infrared and visible wavebands, which is beneficial for infrared–visible compatible stealth. Meanwhile, ZrB2 matrix changes from hydrophilic to hydrophobic due to Ag segregation to the surface.

Rapid multi-property assessment of compositionally modulated Fe-Co-Ni thin film material libraries

Next-generation high frequency, high power density, and high operating temperature electrical machines require superior materials which possess an attractive combination of structural as well as functional properties. Development of such new materials by conventional methods is very slow, expensive, and restricted to a few compositions. Hence, we addressed this challenge by the accelerated assessment of multiple properties of a range of Fe-Co-Ni based material compositions. We utilized the magnetron co-sputtering method to prepare compositionally modulated ternary Fe-Co-Ni thin film alloy (TFA) libraries. The structural, electrical, magnetic, and mechanical properties of these libraries were assessed. The structure and properties were found to vary over a wide range with composition and thin film processing parameters. The Fe-Co-Ni TFA library prepared at a substrate temperature of 500 °C exhibited a good combination of multiple properties. The specific alloy composition Ni54.9Co33.1Fe12 was found to possess an attractive blend of properties. Thus, a rapid property assessment of TFA libraries of a wide range of compositions and processing conditions was successfully used to identify a novel specific composition and processing protocol which exhibited an attractive mix of properties.

Annealing temperature effect on the surface properties and antimicrobial activity of SnSe thin films

In this study, tin selenide thin films with various atomic ratios were fabricated using the RF magnetron co-sputtering method and annealed at different temperatures. In order to observe the structural and chemical properties of the thin films, various characterization tools and methods such as atomic force microscope (AFM), scanning electron microscope (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), ultra-violet photoelectron spectroscopy, Kelvin probe, and antimicrobial test against Escherichia coli were performed. SEM and AFM images showed that the surface morphology of the thin films changed at 573 K. Additionally, the phase changed from amorphous to orthorhombic SnO2 at high temperature, which was confirmed by XRD results. XPS results confirmed SnSe thin films was oxidized and Se evaporated as the annealing temperature increased. The work function of thin films with higher contents of Sn than Se were increased from 5.23 to 5.68 eV as the annealing temperature increased. On the other hand, the work function of thin films with higher Se content than Sn decreased from 5.86 to 5.44 eV. Antimicrobial testing revealed that the SnSe thin films exhibit a stronger effect compared to pure Sn and Se thin films.

Study on capacitance properties of the sputtered carbon doped titanium nitride electrode material for supercapacitor

Titanium nitride doped with carbon film (TiN/C) is designed as the electrode for supercapacitor since the titanium nitride has the pseudocapacitive nature. In this paper, the TiN/C films without any binder are prepared by using magnetron co-sputtering method. The surface of C doped TiN film changes into pyramid shape, which increases the porosity and surface roughness of the film, and enhances the formation of surface pseudocapacitive material TiOxNy, which promotes the super capacitive properties of TiN/C electrode. The TiN film electrode with ∼5.33 at.% doped C displays an outstanding capacitance performance with the maximum areal capacitance of 45.81 mF cm−2. It is 3 times that of the un-doped TiN (16.25 mF cm−2) at a scan rate of 10 mV s−1 in 0.5 M H2SO4 solution. It exhibits excellent electrochemical cycling stability and excellent reversibility with a decay rate of 3.72% after 5000 cycles. In addition, the TiN/C-2 electrode has the great capacitance performance and the large capacitance contribution with the value of 85%. The incorporation of C element to the transition metal nitride could be a feasible method to improve the capacitance performance of transition metal nitride electrode.