Multi-target Magnetron Sputtering Research Articles

Study on Microstructure and Tribological Mechanism of Mo Incorporated (AlCrTiZr)N High-Entropy Ceramics Coatings Prepared by Magnetron Sputtering.

(AlCrTiZrMox)N coatings with varying Mo content were successfully prepared using a multi-target co-deposition magnetron sputtering system. The results reveal that the Mo content significantly affects the microstructure, hardness, fracture toughness, and tribological behavior of the coatings. As the Mo content in the coatings increases gradually, the preferred orientation changes from (200) to (111). The coatings consistently exhibit a distinct columnar structure. Additionally, the hardness of the coatings increases from 24.39 to 30.24 GPa, along with an increase in fracture toughness. The friction coefficient is reduced from 0.72 to 0.26, and the wear rate is reduced by 10 times. During the friction process, the inter-column regions of the coatings are initially damaged, causing the wear track to exhibit a wavy pattern. Greater frictional heat is generated at the crest of the wave, resulting in the formation of a MoO2 lubricating layer. The friction reaction helps to reduce the shear force during friction, demonstrating the lower friction coefficient of the (AlCrTiZrMox)N coatings. Both the hardness and fracture toughness work together to reduce the wear rate, and the (AlCrTiZrMox)N coatings show excellent wear resistance. Most notably, although the columnar structure plays a negative role in the hardness, it contributes greatly to the wear resistance.

Effect of Ta(Cu)–O composite film on mechanical properties, osteoblasts proliferation and antibacterial behavior of medical titanium alloy

Although titanium alloy (Ti–6Al–4V) has good mechanical and biological properties as a bone implant material, it still has defects of biologically inertness and poor antibacterial ability. In this study, a multi-target magnetron sputtering method was used to prepare Ta(Cu)–O composite films with three different ratios (Ta(Cu10.82)-O; Ta(Cu5.68)-O; Ta(Cu3.43)-O) on the surface of Ti–6Al–4V to solve the problems above. In vitro osteoblast proliferation experiments showed that the Ta(Cu)–O composite films significantly accelerated the proliferation, adhesion and spreading of osteoblasts, especially for Ta(Cu3.43)-O. And due to the excellent antibacterial activity of Cu, the Ta(Cu)–O composite films also showed good antibacterial effect. In conclusion, the results showed that the Ta(Cu)–O films can enhance the antibacterial properties of Ti–6Al–4V while accelerating the growth of osteoblasts, displaying great clinical potential in bone-implants applications.

Synthesis, microstructure and properties of MoAlB MAB phase films

MoAlB, given its remarkable properties of both metals and ceramics, has rekindled interest. In this study, MoAlB MAB phase films were fabricated using multi-target direct-current magnetron sputtering (DCMS) and ex-situ annealing, yielding fine, compact, and columnar-free structures. The microstructure evolution of as-deposited films during ex-situ annealing was elucidated. Results revealed that the as-deposited film was amorphous. After ex-situ annealing below 600 °C, the film presented a composite structure comprising nanocrystals embedded in an amorphous matrix, exhibiting the highest values for hardness and Young's modulus, namely 30 ± 2 GPa and 438 ± 15 GPa, respectively. At 600 °C, the film transformed from amorphous to a MoAlB MAB phase without any intermediate compounds, achieving hardness and Young's modulus of 25 ± 3 GPa and 437 ± 30 GPa, respectively. As the temperature was further raised to 700 °C, the film developed a layered structure consisting of sheet-like granular clusters, which exhibited excellent toughness while retaining a high hardness of 18 ± 1 GPa. Besides, the resistivity of the films was predominantly stimulated by the crystal morphology.

(Digital Presentation) Investigation of Top Electrodes Impact on Performance of Transparent Amorphous Indium Gallium Zinc Oxide (a-InGaZnO) Based Resistive Random Access Memory

The traditional von Neumann architecture limits the increase in computing efficiency and results in massive power consumption in modern computers due to the separation of storage and processing units. The novel neuromorphic computation system, an in-memory computing architecture with low power consumption, is aimed to break the bottleneck and meet the needs of the next generation of artificial intelligence (AI) systems. Thus, it is urgent to find a memory technology to implement the neuromorphic computing nanosystem. Nowadays, the silicon-based flash memory dominates non-volatile memory market, however, it is facing challenging issues to achieve the requirements of future data storage device development due to the drawbacks, such as scaling issue, relatively slow operation speed, and high voltage for program/erase operations. The emerging resistive random-access memory (RRAM) has prompted extensive research as its simple two-terminal structure, including top electrode (TE) layer, bottom electrode (BE) layer, and an intermediate resistive switching (RS) layer. It can utilize a temporary and reversible dielectric breakdown to cause the RS phenomenon between the high resistance state (HRS) and the low resistance state (LRS). RRAM is expected to outperform conventional memory device with the advantages, notably its low-voltage operation, short programming time, great cyclic stability, and good scalability. Among the materials for RS layer, indium gallium zinc oxide (IGZO) has shown attractive prospects in abundance and high atomic diffusion property of oxygen atoms, transparency. Additionally, its electrical properties can be easily modulated by controlling the stoichiometric ratio of indium and gallium as well as oxygen potential in the sputter gas. Moreover, since the IGZO can be applied to both the thin-film transistor (TFT) channel and RS layer, it has a great potential for fully integrated transparent electronics application.In this work, we proposed amorphous transparent IGZO-based RRAMs and investigated switching behaviors of the memory cells prepared with different top electrodes. First, ITO was choosing to serve as both TE and BE to achieve high transmittance. A multi-target magnetron sputtering system was employed to deposit all three layers (TE, RS, BE layers) on glass substrate. I-V characteristics were evaluated by a semiconductor parameter analyzer, and the bipolar RS feature of our RRAM devices was demonstrated by typical butterfly curves. The optical transmission analysis was carried out via a UV-Vis spectrometer and the average transmittance was around 80% out of entire devices in the visible-light wavelength range, implying high transparency. We adjusted the oxygen partial pressure during the sputtering of IGZO to optimize the property because the oxygen vacancy concentration governs the RS performance. Electrode selection is crucial and can impact the performance of the whole device. Thus, Cu TE was chosen for our second type of device because the diffusion of Cu ions can be beneficial for the formation of the conductive filament (CF). A ~5 nm SiO2 barrier layer was employed between TE and RS layers to confine the diffusion of Cu into the RS layer. At the same time, this SiO2 inserting layer can provide an additional interfacial series resistance in the device to lower the off current, consequently, improve the on/off ratio and whole performance. Finally, an oxygen affinity metal Ti was selected as the TE for our third type of device because the concentration of the oxygen atoms can be shifted towards the Ti electrode, which provides an oxygengettering activity near the Ti metal. This process may in turn lead to the formation of a sub-stoichiometric region in the neighboring oxide that is believed to be the origin of better performance.In conclusion, the transparent amorphous IGZO-based RRAMs were established. To tune the property of RS layer, the sputtering conditions of RS were varied. To investigate the influence of TE selections on switching performance of RRAMs, we integrated a set of TE materials, and a barrier layer on IGZO-based RRAM and compared the switch characteristics. Our encouraging results clearly demonstrate that IGZO is a promising material in RRAM applications and breaking the bottleneck of current memory technologies.

Improving Mechanical and Tribological Behaviors of GLC Films on NBR under Water Lubrication by Doping Ti and N

Water lubrication has been widely used in marine equipment, where rubber bearings and seals suffer intense friction and severe wear under mixed and boundary conditions. It has good research prospects and practical value to study the composite of amorphous carbon on water lubrication rubber to improve lubrication and reduce wear. In this work, modified graphite-like carbon films incorporated with titanium and nitrogen ((Ti:N)-GLC) were integrated on nitrile butadiene rubber (NBR) with multi-target magnetron sputtering. Direct current (DC) sputtering of graphite target was used as the carbon source. The incorporation of Ti and N elements was accomplished by using radio frequency (RF) magnetron sputtering of three different targets: Ti, TiC and TiN, to optimize the mechanical and tribological performance. This work is aimed to clarify the modification mechanism of Ti and N incorporation and obtain the optimum scheme. The influence of RF power on surface topography, chemical composition, mechanical properties and tribological properties was investigated by SEM, XPS, Raman spectra, nanoindentor and tribometer. The consequences revealed that the characteristics of films depend on RF target types and power. For the Ti-C and TiC-C series, when RF power is 100 W and below, with low content of Ti (6 at.%~13 at.%) and N (around 10 at.%), the incorporation of Ti and N optimizes the surface topology, improves the mechanical properties and maintains excellent adhesion to NBR substrate. The tribological and wear behaviors of (Ti:N)-GLC films are better than GLC films under mixed and boundary lubrication. When RF power grows to 200 W, the dopants result in the deterioration of surface and mechanical properties, followed by worse lubrication and wear behaviors. For TiN-C series, the incorporation of TiN takes no advantage over GLC films, even worse in the case of high RF power. Overall, the incorporation of Ti or TiC by magnetron sputtering in Ar/N2 atmosphere is an effective modification method for GLC films on NBR to improve mechanical and tribological behaviors.

Study on microstructure, mechanical properties and corrosion resistance of NbCN-Cu composite films

In this research, NbCN-Cu films with different Cu contents were prepared by multi-target confocal RF magnetron sputtering. X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), X-ray Photoelectron Spectroscopy (XPS), Raman spectrometry, Energy Disperse Spectroscopy (EDS), nano-indentation, and electrochemical workstation were used to characterize and analyze the microstructure, mechanical properties and corrosion resistance of the films. The results show that the NbCN-Cu composite films consist of crystalline face-centered cubic(fcc) Cu, face-centered cubic(fcc) NbCN, hexagonal close-packed(hcp) NbCN, and amorphous graphite and CNx phases. When Cu content was 2.6 at.%, a coherent interface was detected between fcc-Cu and fcc-NbCN, hcp-NbCN, and dislocations were detected at the coherent interface when Cu content increased to 9.5 at.%. With the increase of Cu content, the microhardness of the film first increased and then decreased. NbCN-Cu composite film with Cu content of 2.6 at.% had the highest hardness of 32.8 GPa and remarkable corrosion resistance. The self-corrosion potential of the film was 0.18 V and self-corrosion current density was 2.29 × 10−6 A/cm2.

Design and Manufacturing of Angular DC Magnetron Co- Sputtering System to Provide Multilayer Films

The research aims to design and produced a new vacuum chamber set of the angular multi-target magnetron sputtering system was supplied by three patterns of the process gas emissions in one system. One pattern supplies the gas directly in front of the target surface, while another pattern supplies the gas beside the chamber, and another pattern supplies the gas to the bottom of the lid. The vacuum chamber set was designed as a top-down sputtering process which has six major components is new designed and produced, consists of the base, the chamber with a window, the feedthrough for the anode pole, the lid, the magnetron target-holder gun, and the rotate substrate-holder set. When the system is completely assembled, then try to test the leakage and plasma ignition until both passes tested, and then a preliminary test of the sputtering process to provide a thin fi lm with sputtered one copper target which was mounted on one gun onto glass slide substrates for the gas emissions of three patterns. After that run sputtering process to provide the multilayers fi lms with three target materials include copper, aluminum, and brass, which was mounted on three guns onto the rotate glass slide substrates. The results of the thin fi lm thickness from the sputtering process was found this system can be used to build a thin fi lm for changing various sputtering voltages, including the system can be successfully used to provide multilayers fi lm and generate argon plasma which was supplied three patterns of the process gas emissions in one system.

Enhanced thermal stability of the metal/dielectric multilayer solar selective absorber by an atomic-layer-deposited Al2O3 barrier layer

To improve the thermal stability of multilayered solar selective absorber, an atomic-layer-deposited (ALD) Al2O3 layer was adopted to suppress the diffusion of metal atoms from the bottom reflection layer. The designed film structure was as that: Cu (>100.0 nm)/Al2O3 (59.8 nm)/Cr (17.8 nm)/SiO2 (66.3 nm)/Cr (4.4 nm)/SiO2 (83.0 nm). Multi-target magnetron sputtering method was employed to fabricate Cu, SiO2, and Cr layers, while for the Al2O3 layer, it was prepared by ALD. The sample has a solar absorptance of about 95.4% and a thermal emittance of 0.196 at the temperature of 773 K. The sample with the Al2O3 barrier layer work stably at 500 °C for 72 h, demonstrating that the proposed multilayer solar selective absorber is suitable for applications at middle-temperature solar thermal conversion systems.

The effect of molybdenum content on microstructure, mechanical, tribological and corrosion behavior of Zr-Mo-N composite films

In this research, Zr-Mo-N composite films with different Mo content were deposited by multi-target magnetron sputtering device. The first-principle calculation, X-ray diffraction (XRD), high-resolution transmission electron microscopy (HR-TEM), scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDS), nano-indentation, high-temperature sliding wear tests and electrochemical workstation were used to characterize the microstructure, mechanical, tribological and corrosion behavior of Zr-Mo-N films. The results showed that molybdenum atoms replaced the zirconium atoms in ZrN lattice to form a (Zr, Mo) N solid solution. Zr-Mo-N films exhibited a face-centered cubic (fcc) structure less than the content of 11.3 at.% Mo, and showed a double phase of fcc-ZrN and fcc-Mo2N when Mo content reached 11.3 at.%. With the increase of Mo content, the hardness first increased and then decreased, which maximum value was obtained at 11.3 at.% Mo. The friction coefficient at room temperature decreased monotonically, meanwhile the wear rate first decreased and then increased with the best value showed at 16.9 at.% Mo. The wear test under elevated temperature showed the friction coefficient of films initially increased and then decreased with the raising test temperature, as well as the monotonically increase of wear rate. The films represent the best corrosion resistance when the Mo content is 11.3 at.%.

Self-Powered Smart Insole for Monitoring Human Gait Signals.

With the rapid development of low-power consumption wireless sensors and wearable electronics, harvesting energy from human motion to enable self-powered sensing is becoming desirable. Herein, a pair of smart insoles integrated with piezoelectric poly(vinylidene fluoride) (PVDF) nanogenerators (NGs) are fabricated to simultaneously harvest energy from human motion and monitor human gait signals. Multi-target magnetron sputtering technology is applied to form the aluminum electrode layers on the surface of the PVDF film and the self-powered insoles are fabricated through advanced 3D seamless flat-bed knitting technology. Output responses of the NGs are measured at different motion speeds and a maximum value of 41 V is obtained, corresponding to an output power of 168.1 μW. By connecting one NG with an external circuit, the influence of external resistance, capacitor, and motion speed on the charging characteristics of the system is systematically investigated. To demonstrate the potential of the smart insoles for monitoring human gait signals, two subjects were asked to walk on a treadmill at different speeds or with a limp. The results show that one can clearly distinguish walking with a limp from regular slow, normal, and fast walking states by using multiscale entropy analysis of the stride intervals.

Influence of V content on properties of Ti–W–V–N films

ABSTRACTTi–W–V–N composite films with different vanadium contents were synthesised by multi-target reactive magnetron sputtering. The microstructure, mechanical and tribological properties of Ti–W–V–N films were investigated by X-ray diffraction, scanning electron microscope, high-resolution transmission electron microscopy, nanoindentation and high-temperature ball-on-disc tribometer. The results showed that all the Ti–W–V–N composite films were face-centred cubic (fcc) structure, consisting of fcc-(Ti,W,V)N substitutional solid solution. When the V content ≥21.5 at.-%, the films consisted of fcc-(Ti,W,V)N and fcc-VN. The hardness of the films first increased and then decreased with the maximum value of 32.4 GPa, at 21.5 at.-% V. The test temperature had a significant effect on the tribological properties of Ti–W–V–N film with 21.5 at.-% V, the coefficient of friction (CoF) first increased and then decreased, with a minimum value of 0.304 at 700°C.While the wear rate increased gradually with increasing temperature.

Influence of Ag Content on Microstructure, Mechanical and Tribological Properties of WNbN-Ag Composite Films

WNbN composite films with different Ag content were deposited by reactive multi-target magnetron sputtering. The microstructure, mechanical and tribological properties were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), high resolution transmission electron microscopy (HRTEM), nano-indentation and ball-on-disc tribo-mter analysis. The results indicated that WNbN-Ag film consists of face-centered cubic (fcc) WNbN, face-centered cubic (fcc) NbN, hexagonal close-packed (hcp) NbN and face-centered cubic (fcc) Ag. The hardness and elastic modulus of WNbN-Ag composite film decreases gradually as Ag content increases from 0 to 25.23 at %. At room temperature, the friction coefficient of the film firstly increases and then decreases, while the wear rate gradually increases with the increasing Ag content. As the temperature increases from room temperature to 700°C, the friction coefficient firstly increases and then decreases, while the wear rate gradually increases. The tribological properties of the film depended on the testing temperatures significantly because the testing temperatures influenced the hardness, the tribo-films and wear mechanism of the film.

Fabrication of highly electrically conductive Ti/Ag/Ti tri-layer and Ti–Ag alloy thin films on PET fabrics by multi-target magnetron sputtering

In this study Ti/Ag/Ti tri-layer and Ti–Ag alloy films were deposited on the surfaces of polyethylene terephthalate (PET) fabrics by multi-target magnetron sputtering system to fabricate highly electro-conductive textiles. Before sputtering, the fabric was treated by polyacrylic acid ester (PA) to form a continuous surface on the surface of PET fabric by padding method. The as-fabricated fabrics were characterized by scanning electron microscopy, X-ray diffraction, and Fourier transform infrared spectrometer. And the physical properties of the coated fabrics were evaluated by electrical conductivity, contact angle (CA), flexibility and adhesion. At last, a simple electric circuit was made with the as-treated fabric to evaluate the electrical property and explore its application further. The results of the study revealed that pretreatment with PA could form a continuous film on the surface of PET fabric. The PA-coated PET fabric with Ti/Ag/Ti fabric exhibited excellent electrical property whose electrical resistivity was only 5.1 × 10−7 Ω m, CA of 137°. The PA-coated PET fabric with Ti–Ag alloy film exhibited a rather lower electrical resistivity of 3.4 × 10−7 Ω m, CA of about 130°. Moreover, the samples retain ideal flexibility and adhesion. Therefore this study can broaden the application area of magnetron sputtering on discontinuous surface to fabricate electrical conductive fabric. And due to the excellent electro-conductivity, this kind of fabric will be a promising material for smart textiles.

Performance evaluation of HSS cutting tool coated with hafnium and vanadium nitride multilayers, by temperature measurement and surface inspection, on machining AISI 1020 steel

The hard coatings application on cutting tools improves the lifetime, performance and also quality of the workpiece, usually by increasing the wear resistance. Hafnium nitride and vanadium nitride multilayer coatings [HfN/VN]n present mechanical, tribological and physical-chemical properties that have been identified previously by other authors and are desirable for cutting tools. With physical vapor deposition (PVD) of hafnium nitride/vanadium nitride [HfN/VN]n multilayer coatings were deposited with bilayer numbers n=1, n=50 and n=80 onto High-speed steel (HSS) cutting tools by using the Multi-target Magnetron Sputtering technique, the machining tools used as a substrate were burin ASSAB 17 steel. The uncoated tools and coated tools with HfN/VN multilayers were used to machine AISI 1020 steel bars at the same turning parameters by using a CNC machine. The cutting efficiency, machining quality, and tool wear are influenced by coating nature and the temperature, therefore, as an evaluation method the tool temperature, the steel temperature, and the machining chip temperature were measured by means an infrared sensor. The data analyses were carried out in MatLab, to identify average temperature and temperature rate for all machining tools. The superficial roughnesses (Ra) of workpieces were evaluated by using a roughness tester. Tool wear and surface wear mechanism were analyzed through Scanning Electron Microscopy (SEM). In this work it was found that temperature rates on machining tools and on machined workpieces were decreased, in relation to chip temperatures which exhibit an increasing. The workpiece roughness was reduced around 28%, and the wear rate was reduced around 50%, in relation to the uncoated and coated tools with [HfN/VN]n multilayers. Results showed in this research reveal that [HfN/VN]n multilayers, as function of bilayer number (n), improve the lifetime of the cutting tools due to the reduction of energy transfer and the increase in wear resistance, with low friction coefficient between cutting tool and workpiece evidenced in the surface roughness associated to the workpiece.

Diamond like carbon coatings doped by Si fabricated by a multi-target DC-RF magnetron sputtering method - Mechanical properties, chemical analysis and biological evaluation

Doped diamond-like carbon coatings (DLC) are a promising solution for improvement of the performance of medical implants. Among various additives that can alter either mechanical or biological properties of DLC, silicon is a possible choice.This work focuses on the improvement of mechanical and biological properties by silicon incorporation into a DLC matrix. The successful deposition of Si-DLC coatings was demonstrated by FTIR spectra revealing the presence of Si-C, Si-O-Si and Si-Mex bonds (where Me – methyl group). The amount of dopant ranged from ∼ 1.2 at.% to∼ ∼ 21.9 at.%. Increasing the Si content resulted in the increase of hydrophilic character of the doped DLC coatings. Incorporation of silicon also increased the films' hardness, by 40% in the case of the most highly-doped coating. The biological evaluation with use of human osteosarcoma cells (Saos-2) revealed the possibility of tailoring the proliferation of mammalian cells by varying the amount of silicon dopant in such coatings. All of the examined coatings reduced the microbial colonisation of E. coli bacteria, compared to uncoated substrate.The most highly-doped coating was shown to be the most promising material among the examined samples for biomedical use, due to exhibiting highest hardness and critical force as well as low number of adhered bacteria.

Mechanical properties, chemical analysis and evaluation of antimicrobial response of Si-DLC coatings fabricated on AISI 316 LVM substrate by a multi-target DC-RF magnetron sputtering method for potential biomedical applications

In this study silicon doped diamond-like carbon (Si-DLC) coatings were synthesized on two substrates: silicon and AISI 316LVM stainless steel using a multi-target DC-RF magnetron sputtering method. The Si content in the films ranged between 4 and 16at.%, and was controlled by the electrical power applied in RF regime to Si cathode target.The character of the chemical bonds was revealed by FTIR analysis. With the addition of silicon the hydroxyl absorption (band in the range of 3200–3600cm−1) increased what suggests more hydrophilic character of the coating. There were also observed significant changes in bonding of Si atoms. For low content of dopant, Si-O-Si bond system is predominant, while for the highest content of silicon there is an evidence of the shift to Si-C bonds in close proximity to methyl groups. The Raman spectroscopy revealed that the G peak position is shifted to a lower wavenumber and the ID/IG ratio decreased with increasing Si content, which indicates an increase in the C-sp3 content. Regardless of the coatings’ composition, the improvement of hardness in comparison to pure substrate material (AISI 316 LVM) was observed. Although the reduction of the level of hardness from the level of 10.8GPa for pure DLC to about 9.4GPa for the silicon doped coatings was observed, the concomitant improvement of films adhesion with higher amount of Si was revealed. Although incorporation of the dopant to DLC coatings increases the number of E. coli cells which adhered to the examined surfaces, the microbial colonisation remains on the level of substrate material.The presented results prove the potential of Si-DLC coatings in biomedical applications from the point of view of their mechanical properties.

Microstructure, mechanical and tribological properties of TaCN composite films

Tantalum and carbon nitride films, with varied power of the carbon target were synthesised by multi-target magnetron sputtering. The microstructure, mechanical and tribological properties of TaCN films were investigated by X-ray diffraction, Fourier transform infrared spectroscopy, atomic force microscopy, scanning electron microscopy, nano-indentation, nano-scratch, and a high temperature ball-on-disc tribometer. X-ray diffraction reveals that these films exhibit face centred cubic and base centred orthorhombic crystal structures, regardless of the power of the carbon target. At 50 W, the hardness, critical loads for cohesive failure (Lc1) and critical loads for adhesive failure (Lc2) of these films reach a maximum, 28·6 GPa, 4·52 N and 8·1 N, respectively, while at 80 W, the lowest average friction coefficient and wear rate of TaCN films are obtained, measured as 0·36 and 2·91×10−7 mm2 N−1, respectively.

XRD and AFM Studies on Nanostructured Zinc Aluminum Oxide Thin Films Prepared by Multi-Target Magnetron Sputtering

Zinc Aluminum Oxide (ZAO) thin films have been deposited on glass substrates by DC reactive magnetron co-sputtering at different sputtering powers of Zn varied from 85 to 125 W. X-ray diffraction patterns exhibits ZAO thin films had a diffraction peak corresponding to (0 0 2) preferred orientation with c-axis perpendicular to the substrate surface. X-ray diffraction patterns have been used to determine the structural parameters such as crystallite size, stress, strain and lattice constants. The image processing of atomic force microscopy data provides quantitative information on nanostructured ZAO thin films. Statistics on groups of particles are measured through image analysis and data processing includes particle counts, particle size distribution, surface area distribution and volume distribution. The average roughness, maximum peak to valley height, root mean square roughness, ten-point mean height roughness, surface skewness and surface kurtosis parameters are used to analyze the surface topography of ZAO films.

Influence of silver content on structure, mechanical and tribological properties of WCN–Ag films

In recent years, the preparation of thin films with excellent tribological properties over a wide temperature range has attracted the attention of the researchers. It is reported that an effective way is the fabrication of films consisting of different lubricant phases, which exhibit self-lubricating characteristics at different temperatures. On this basis, WCN–Ag films with various silver contents ranging from 0 to 8.3at.% were deposited by a multi-target magnetron sputtering system. The composition, structure, mechanical and tribological properties were characterized using XPS, XRD, HRTEM, nano-indentation, ball-on-disk dry sliding wear tester, Bruker 3D Profiler, SEM and compared to WCN. It is found that the incorporation of silver does not change the cubic structure, WCN–Ag films consist of a mixture of WCN, W2N, Ag, amorphous C and CNx phases. Although the addition of Ag into WCN films reduces the hardness, Young's modulus and compressive stress, it improves the tribological properties obviously. A low friction coefficient (<0.4) is observed in the temperature range of 25–600°C for WCN–Ag film containing 6.6at.% Ag. Overall, the results reveal that WCN–Ag films by adding some Ag content can exhibit self-lubricating characteristics in the temperature range of 25–600°C.

Multitarget Sputtering of Piezoelectric Mixed Oxide Thin Films onto Flexible Substrates

Large area film deposition was performed by means of multitarget reactive magnetron sputtering from metallic targets (Pb, Ti, Zr) with a diameter of 200 mm onto Cu-coated Kapton® HN substrates. High-power pulse sputtering has been employed for the Zr-target (or alternatively for the Ti-target). Film composition profiles were evaluated by XPS and RBS. Piezoelectric properties were investigated by PFM.