Reactive Unbalanced Magnetron Sputtering Research Articles

High-temperature oxidation resistance of CrAlN thin films prepared by DC reactive magnetron sputtering

CrAlN thin films were prepared by using the reactive DC unbalanced magnetron sputtering method from the single alloy target on a silicon substrate. The effect of annealing temperature in the air which ranges from 500℃ to 900℃ for 1 h on phase structure, film composition, surface morphology, microstructure, and hardness was investigated by XRD, EDS, FE-SEM, and Nanoindentation techniques, respectively. The high-temperature (up to 900℃) oxidation resistance of the thin film was also evaluated. The result shows that solid solutions of (Cr,Al)N with (111), (200), and (220) planes for the as-deposited film and no oxide phase were found after annealing with different temperatures. The O content slightly increases with an increase in the annealing temperature with various Cr, Al, and N contents found by the EDS. From the FE-SEM result, as increased annealing temperature, the evolution of cross-sectional morphology from dense to compact columnar structure was exhibited but the oxides layer was not detected. These results concluded that the as-deposited thin film showed good oxidation resistance when annealed in air at an elevated temperature reaching 900℃. Moreover, the film’s hardness decreased from 61.19 GPa to 50.11 GPa with increasing the annealing temperature observed by the Nanoindentation technique.

Wettability and corrosion resistance of zirconium nitride films obtained via reactive high-power impulse magnetron sputtering

One of the main problems in ships is corrosion, which reduces the lifetime usage of ship parts and increases maintenance costs. Ceramic coatings can contribute to solving this situation. Zirconium nitrides obtained by reactive unbalanced magnetron sputtering technology are largely reported as coatings with high corrosion resistance. The present study used high-power impulse magnetron sputtering in a reactive atmosphere (R-HiPIMS), varying the nitrogen amount. SEM, EDS, XRD, AFM, and contact angle measurements were used to assess the obtained coatings’ performance. Corrosion resistance was evaluated using electrochemical impedance spectroscopy (EIS) (up to 168 h exposure) and potentiodynamic polarization (PP) in NaCl (3.5% wt.—“artificial seawater”) solution. According to the results, cross section micrographs showed strong densification of ZrN films regardless of the nitrogen amount. Besides, nitrogen increases during deposition influenced the drop of applied peak power (Pp) to the target and, consequently, influenced other film properties, such as roughness, wettability, and corrosion resistance. PP and EIS tests demonstrate the protective behavior of films under artificial seawater exposure. The results prove that the implementation of HiPIMS technology to obtain ZrN films could contribute to increasing the corrosion resistance of coated ship metallic parts and, hence, help maritime transportation to reduce maintenance time and cost.

The Effect of TiN, TiAlN, TiCN Thin Films Obtained by Reactive Magnetron Sputtering Method on the Wear Behavior of Ti6Al4V Alloy: A Comparative Study

Titanium-based alloys have gained worldwide application over the past century. However, their low wear resistance remains an unresolved challenge for the Ti6Al4V alloy, which has significant industrial use. Therefore, it is an integral part in material selection and surface treatment in friction-wear applications. Tribological properties are not only material parameters but also system parameters where test conditions are essential. Hardness, roughness and contact conditions of coatings, which are especially important in surface treatments, affect wear modes. In this study, titanium nitride, titanium aluminum nitride and titanium carbon nitride coatings were obtained by unbalanced reactive magnetron sputtering to improve the weak tribological properties of Ti6Al4V alloy. The wear behavior was studied at room temperature in dry conditions. Wear tests were conducted under different loads and different sliding rates, which were followed by comparative analyses of their wear resistances. While the coated samples showed higher wear resistance than the uncoated Ti6Al4V alloy, the lowest wear track width was observed in TiN coating. Depending on the surface properties of the coatings, adhesion, abrasion and oxidation wear mechanisms were observed. It was concluded that a TiN coating could be a material of choice for applications where triple abrasive wear is dominant.

HIPIMS/UBM PVD Coating Equipment Designed to Coat Universal Sized Broaches

This paper describes a physical vapor deposition (PVD) coating equipment, as well as the according deposition parameters suitable to provide hard nitride coatings on broaches up to a length of 2.2 m. The octagonal-shaped vacuum chamber reached a height of 4.5 m and a diameter of 1.2 m. To explore a sufficient and reproducible film, an adhesion test sample and tools were subjected to a pretreatment in a Cr2+ Ar+ high-power impulse magnetron sputtering (HIPIMS) plasma prior to the actual film deposition. Two deposition methods were applied: reactive unbalanced magnetron (UBM) sputtering was introduced to deposit TiAlN-based coatings from Ti50Al50 2.5 m long targets. Alternatively, multilayer coatings were generated by reactive simultaneous UBM sputtering from Ti50Al50 and TiAl6V4 targets, respectively, and chromium targets utilizing high-power impulse magnetron sputtering (HIPIMS) technology. In the latter case, three cathodes were furnished with 0.9 m long targets lined up upon each other. A segmented UBM cathode design was described to meet economic deposition if varying tool sample lots in the deferring workpiece lengths have to be handled in industrial practice. The resulting (TiAl/Cr)N multilayer coatings attained typical hardness values of HV 2800 and an adhesion measured by critical load up to 50 N. The cutting performance of this coating was evaluated by simulated shaping tests over a test length of 210 m on C 45 steel. The (TiAlV/Cr)N showed an improved wear behavior by factor of 2 to 3 compared to TiN deposited by cathodic arc operated in an industrial PVD coater. A real comparison was undertaken, applied to a 1.3 m long model broach. (TiAl/Cr)N showed a prolongation in industrial lifetime by 150% compared to TiN.

A facile synthesis of Al-doped BaTiO3 thin films by a hydrothermal-galvanic couple method on TiAlN film electrodes

Al-doped barium titanate (ABT) thin films were produced by a facile hydrothermal-galvanic couple (HT-GC) method using ternary TiAlN seeding layers. TiAlN thin films serving as the working electrode were deposited onto Si substrates by reactive unbalanced magnetron sputtering. HT-GC synthesis was conducted in the alkaline solutions consisting of 0.5 M Ba(CH3COOH)2 and 2 M NaOH. Although no external power sources were applied, substantial galvanic currents occurred during the synthesis. X-ray diffraction patterns show that cubic ABT films were formed over TiAlN. Field-emission scanning electronic microscopy revealed ABT films exhibiting hemispherical grains over the nitride surface with single-layered structures. X-ray photoelectron spectroscopy verified Al doping in the obtained ABT coatings. Reaction paths and formation mechanisms of the ABT coatings were also proposed. Moreover, the ABT thin films possessed higher residual polarization (Pr) and piezoelectricity coefficient (d33) compared with un-doped BaTiO3 (BTO), deduced from polarization–electric field loops results. The deduced Pr-value for BTO thin films was 0.8 μC/cm2 and could be enhanced to 1.6 μC/cm2 for ABT thin films, meanwhile the value of d33 for BTO films was 13 ± 1 pC/N and increased to 18 ± 1 pC/N for ABT films. Such a facile synthesis of ABT thin films may bring in more technological applications such as piezoelectric and triboelectric materials in the hybrid nanogenerator, and non-volatile ferroelectric random access memory.

Preclinical Study of a Multi-Layered Antimicrobial Patch Based on Thin Nanocomposite Amorphous Diamond Like Carbon Films with Embedded Silver Nanoparticles.

A growing number of severe infections are related to antibiotic-resistant bacteria, therefore, in recent years, alternative antimicrobial materials based on silver nanoparticles (NPs) attracted a lot of attention. In the current research, we present a medical patch prototype containing diamond-like carbon nanocomposite thin films doped with silver nanoparticles (DLC:Ag), as a source of silver ions, and an aqueous mass of the gelatin/agar mixture as a silver ion accumulation layer. The DLC:Ag thin films with 3.4 at.% of silver were deposited on synthetic silk employing reactive unbalanced DC magnetron sputtering of the silver target with argon ions performed in the acetylene gas atmosphere. The average size of the silver nanoparticles as defined by scanning electron microscope was 24 nm. After the film deposition, the samples were etched with RF oxygen plasma, aiming at efficient silver ion release in aqueous media from the nanocomposite film. In the patch prototype, a mixture of agar and gelatin was applied in silicone carrier with cavities, acting as a silver ion accumulation layer that further enhanced the antimicrobial efficiency. It was found that the DLC:Ag thin film on the silk after soaking in water for 24 h was able to release up to 4 ppm of Ag. The microbiological experiments using S. aureus bacteria were performed with the patch prototype and the silver ion saturated water, demonstrated the inactivation of 99% and 79% of bacteria, respectively. Scanning electron microscopy analysis showed that silver NPs destroyed the bacteria cell and the bacteria affected by Ag ions had spots and perforated cell wall areas with cytoplasm leakage out was obtained. A preliminary preclinical study using the laboratory animals demonstrated that using the patch prototype, the methicillin-resistant S. aureus (MRSA)-infected wound on skin surface healed faster compared with control and was able to kill all MRSA bacteria strains in the wound’s bed after 72 h of treatment.

Fracture properties of thin film TiN at elevated temperatures

We provide an experimental and theoretical description of the high temperature fracture behaviour of TiN thin films. For this, we employ molecular dynamics and density functional theory, to show that the surface energies drop insignificantly between 0 and 1000 K. We utilise these results to predict a slight decrease of the fracture toughness over the aforementioned temperature range.For the experimental perspective, we use unbalanced DC reactive magnetron sputtering to synthesise a TiN film, on which we perform in situ high temperature microcantilever bending tests. Upon increasing the testing temperature from room temperature to 773 K our results present a slight, irreversible decrease of KIC, once the deposition temperature of the film (~653 K) is exceeded.Based on our theoretical groundwork, as well as complementary data produced by X-ray diffraction, nanoindentation, transmission electron microscopy, and wafer curvature measurements, we identify growth defect recovery as the main reason behind the decrease of KIC. We observe no change in the deformation and/or fracture mechanism of TiN across the experimentally investigated temperature range. Using an analytical model based on continuum mechanics, we estimate the influence of macro residual stresses on the temperature-dependent fracture toughness of TiN attached to a Si (100) wafer.

Reactively sputtered TiN/SiO2 multilayer coatings with designed anisotropic thermal conductivity – From theoretical conceptualization to experimental validation

Wear resistant coatings are frequently used for cutting applications due to their high hardness, chemical stability and low thermal conductivity. The low thermal conductivity is generally believed to redirect the heat generated during cutting into the chip, while the heat transfer into the tool is kept low. However, a low isotropic thermal conductivity of the applied coatings consequently causes high lateral thermal gradients close to the heat affected zone. These gradients in turn might cause local degradation of mechanical properties, increased local wear and pronounced local thermal stress. A promising concept for thermal management during cutting is the use of coatings with designed anisotropic thermal conductivity. Thereby, the heat flow into the tool can be still kept low, while heat dissipation within the coating can be maximized. Following this concept, the focus of this work is the design, deposition and characterization of coatings with tailored anisotropic thermal conductivity. TiN/SiO2 multilayer coatings with periodicities between ~100 and ~400 nm and different TiN/SiO2 thickness ratios resulting in theoretical anisotropy factors ranging from ~1.7 to ~4.0 were designed. Subsequently, corresponding coatings were deposited by unbalanced reactive magnetron sputtering to a total thickness of ~12 μm using Ti and Si targets. The multilayers were prepared for cross-sectional measurements of their in-plane and surface measurements of their cross-plane thermal conductivity by time-domain thermoreflectance to successfully verify the predicted anisotropies.

Surface blistering in ZrSiN nanocomposite films irradiated with He ions

In the present work, the influence of silicon content on the surface blistering of ZrSiN nanocomposite films after He ion irradiation (energy of 30 keV and doses up to 8 × 1016 cm−2) and post-radiation annealing at the temperature of 600 °C was investigated. Using SEM, TEM and AFM methods, the influence of amorphous/crystalline boundaries on the formation of blisters in the n-ZrN/a-Si3N4 nanocomposites was studied. ZrSiN nanocomposite films (~300 nm thick) were deposited at 600 °C onto (001) Si wafers by reactive unbalanced magnetron sputtering technique. Silicon concentration was varied from 7.1 to 23.1 at.%. While helium ion irradiation (at the dose of 8 × 1016 cm−2) did not change the surface morphology of the nanocomposite films, the alteration of the surface was observed after vacuum annealing. It was revealed that post-radiation annealing (600 °C) of ZrN and Si3N4 mononitride films resulted in surface blistering at the dose of 5 × 1016 cm−2. Rather low blister density (0.017 μm−2) after post-radiation annealing at the dose of 5 × 1016 cm−2 was also observed for the nanocomposite film with 7.1 at.% Si content. As the irradiation dose increased up to 8 × 1016 cm−2, the surface density of blisters raised significantly (0.53 μm−2). It was found that increasing of Si concentration in the nanocomposite films was beneficial for their radiation resistance. The ZrSiN nanocomposite film with maximum Si content of 23.1 at.% was the most stable, with no sign of surface blistering being detected.

Fracture Properties of TiN at Elevated Temperatures

Exploring a crucial, yet largely unmapped, territory, we provide an experimental and theoretical description of the high temperature fracture behaviour of TiN thin films. We employ molecular dynamics (MD) and density functional theory (DFT), to show that the (100), (110), and (111) surface energies drop insubstantially between 0 and 1000 K. We utilise these results to predict a slight decrease of the fracture toughness KIC by 4 to 7 % - depending on the orientation - over the aforementioned temperature range.For the experimental perspective, we use unbalanced DC reactive magnetron sputtering to synthesise a TiN film, on which we perform in situ high temperature microcantilever bending tests. Upon heating from room temperature to 773 K (500°C) our results present a slight decrease of KIC from 2.9 ± 0.1 to 2.5 ± 0.1 MPa√m - irreversible upon cooling - only once the deposition temperature (~653 K) is exceeded. Based on our theoretical groundwork, as well as complementary data produced by X-ray diffraction and nanoindentation, we identify recovery of growth defects as the main reason behind the decrease of KIC. We observe no change in the deformation and/or fracture mechanism of TiN across the experimentally investigated temperature range.

Development and testing of multicomponent fuel cladding with enhanced accidental performance

Abstract Accident Tolerant Fuels have been widely studied since the Fukushima-Daiichi accident in 2011 as one of the options on how to further enhance the safety of nuclear power plants. Deposition of protective coatings on nuclear fuel claddings has been considered as a near-term concept that will reduce the high-temperature oxidation rate and enhance accidental tolerance of the cladding while providing additional benefits during normal operation and transients. This study focuses on experimental testing of Zr-based alloys coated with Cr-based coatings using Physical Vapour Deposition. The results of long-term corrosion tests, as well as tests simulating postulated accidents, are presented. Zr–1%Nb alloy used as nuclear fuel cladding serves as a substrate and Cr, CrN, CrxNy layers are deposited by unbalanced magnetron sputtering and reactive magnetron sputtering. The deposition procedures are optimized in order to improve coating properties. Coated as well as reference uncoated samples were experimentally tested. The presented results include standard long-term corrosion tests at 360∘C in WWER water chemistry, burst (creep) tests and mainly single and double-sided high-temperature steam oxidation tests between 1000 and 1400∘C related to postulated Loss-of-coolant accident and Design extension conditions. Coated and reference samples were characterized pre- and post-testing using mechanical testing (microhardness, ring compression test), Thermal Evolved Gas Analysis analysis (hydrogen, oxygen concentration), optical microscopy, scanning electron microscopy (EDS, WDS, EBSD) and X-ray diffraction.

Optimization of W/WAlSiN/SiON/SiO2 tandem absorber consisting of double layer anti-reflection coating with broadband absorption in the solar spectrum region

A novel spectrally selective tandem stack of W/WAlSiN/SiON/SiO2 was deposited on stainless steel 304 and silicon substrates using a four-cathode reactive unbalanced magnetron sputtering system. The coatings were deposited by sputtering of W, Al and Si targets in Ar, Ar + N2, Ar + N2 + O2, and Ar + O2 plasmas. The process parameters were optimized by studying the optical properties of the individual layers using UV-VIS-NIR spectrophotometer and Fourier transform infrared spectroscopy measurements. The high spectral selectivity of the tandem stack was achieved by varying the reactive gas flow rates of N2 and O2 and thickness of individual layers. In the tandem stack, W layer acts as an IR reflector, WAlSiN acts as the main absorber layer, SiON, and SiO2 layers act as anti-reflecting layers. The tandem stack was designed based on graded refractive indices of individual layers with a double layer anti-reflection coating. The tandem stack exhibits superior spectral selectivity with a high solar absorptance of 0.955 in the broadband solar spectrum region and low thermal emissivity of 0.10 in the infrared region. The coating was found to be thermally stable up to 600 °C in vacuum for 200 h under cycling heating conditions.

Deformation and Cracking Mechanism in CrN/TiN Multilayer Coatings

In this study, the effects of the microstructural properties on the deformation and damage mechanism of CrN/TiN multilayer coatings deposited on Custom 450 steel using the unbalanced reactive magnetron sputtering PVD process were studied. All coatings were fabricated with an overall thickness of 1.5 µm, but different bilayer periods (Λ). Structural and mechanical properties of coatings were investigated by XRD analysis and nanoindentation experiment, respectively. Indentation tests at three loads of 100, 300, and 450 mN were performed on the coatings’ surface and then, cross-sections of fractured imprints were analyzed with SEM and TEM. Measuring the length of the cracks induced by indentation loads and analyzing the load-displacement curves, apparent fracture energy values of multilayer coatings were calculated. We observed that multilayer systems with bilayer periods of 4.5–15 nm possess superlattice structure, which also results in higher values for Young’s modulus and hardness as well as higher fracture energy. Comparison of cross-sectional SEM and TEM observations showed that coatings with smaller bilayer periods tend to deform by shear sliding mechanism due to the existence of the long-grown columns, while short dispersed grains—growing in the coatings with a larger bilayer period—led to deformation via local grain boundary sliding and grain rotation.

Effect of Substrate-Target Distance on the Structure of TiCrN Films Deposited from Mosaic Target by Reactive DC Magnetron Sputtering

Titanium chromium nitride (TiCrN) thin films were deposited on Si substrates by reactive DC unbalanced magnetron sputtering from the Ti-Cr mosaic target. The effect of substrate-to-target distances (dst) on the structure of TiCrN thin films were investigated. The crystal structure, microstructure, thickness, roughness and chemical composition were characterized by glancing angle X-ray diffraction (GAXRD), field emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM) and energy dispersive X-ray spectroscopy (EDS) technique, respectively. The results showed that, all the as-deposited films were formed as a (Ti,Cr)N solid solution. The as-deposited films exhibited a nanostructure with a crystal size less than 65 nm. The crystal size of all plane were in the range of 36.3 – 65.7 nm. The lattice constants were in the range of 4.169 Å to 4.229 Å. The thickness and roughness decrease from 500 nm to292 nm and 3.6 nm to 2.2 nm, respectively, with increasing the substrate-to-target distance. The chemical composition, Ti, Cr and N contents, of the as-deposited films were varied with the substrate-to-target distance. The as-deposited films showed compact columnar and dense morphology as a result of increasing the substrate-to-target distance.

Effect of gas mixing ratio on structural characteristics of titanium dioxide nanostructures synthesized by DC reactive magnetron sputtering

In this work, high-quality and highly pure titanium dioxide nanostructures were synthesized by a homemade dc closed-field unbalanced reactive magnetron sputtering system. The operation parameters of the magnetron sputtering system were optimized to prepare TiO2 nanostructures as thin films on glass substrates. These nanostructures were characterized by x-ray diffraction, atomic force microscopy and Fourier-transform infrared spectroscopy. Both anatase and rutile phases were identified. The mixing ratio of argon and oxygen (Ar:O2) gases was found very important to control the structural characteristics of the prepared nanostructures.

Structural and morphological properties of TiN deposited by magnetron sputtering

This work studied the simultaneous effect of multiple parameters on the microstructure and topography of TiN thin films deposited by reactive unbalanced DC magnetron sputtering. The simultaneous influence of deposition parameters including pressure, temperature, and power on crystallite size, texture coefficient, microstructure, and roughness parameters was investigated using design of experiments (DoE): the Taguchi method. The results showed that the mean crystallite size of (111) and (200) planes increase when the temperature and cathode power increase. Furthermore, the increase of cathode power from 50 to 150 W augments the mean of root mean square height (Sq) from 2 to 10 nm. However, the substrate temperature has no considerable effect on the roughness parameters of the surface. Cathode power has also a prominent influence on the skewness of deposited layers in which it abruptly decreases when the power changes from 100 W to 150 W. In other words, all samples deposited at 150 W have negative skewness. It was also shown that the deposition rate is mainly controlled by the cathode power.

Epitaxial titanium nitride on sapphire: Effects of substrate temperature on microstructure and optical properties

Titanium nitride (TiN) is a mechanically robust, high-temperature stable, metallic material receiving considerable attention for resilient plasmonics. In this work, the authors fabricated six heteroepitaxial TiN films on sapphire using controllably unbalanced reactive magnetron sputtering. They examined the effect of substrate growth temperature on the plasmonic and crystalline quality of the film. Optical properties of all films were obtained from spectroscopic ellipsometry; plasmonic quality factors were determined from the real and imaginary parts of the dielectric function. The authors determined crystallinity using x-ray diffraction and surface morphology using atomic force microscopy. X-ray diffraction showed (111) TiN peaks with Pendellösung fringes indicating consistent heteroepitaxy. Atomic force microscopy showed smooth surfaces with root mean square surface roughness ranging from 0.2 to 2.6 nm. Based on this characterization, the authors determined that the substrate deposition temperature of 550 °C yielded (111)-oriented heteroepitaxial TiN with minimal surface roughness. The authors found that 550 °C also gave highest plasmonic quality factors for all wavelengths, approaching the values of today's best plasmonic materials (such as Au and Ag). Further, the Q-factors at wavelength 1550 nm inversely correlated with calculated lattice constants. Their results indicate that the plasmonic response of TiN is directly linked with structural quality of the film.

Diamond like carbon Ag nanocomposites as a control measure against Campylobacter jejuni and Listeria monocytogenes on food preparation surfaces

The effect of thin (5nm) and thick (40nm) silver layers and diamond like carbon nanocomposites with embedded Ag nanoparticles (DLC:Ag) against two reference strains of C. jejuni NCTC 11168 and L. monocytogenes ATCC 7644 were evaluated in this study. DLC:Ag film contained 22at.% Ag. Silver nanoparticle size measured by transmission electron microscope was in the 5–10nm range. Ag layers and DLC:Ag nanocomposites were deposited employing unbalanced reactive magnetron sputtering on crystalline silicon wafers. C. jejuni and L. monocytogenes numbers were counted by culture-based enumeration on selective agars and quantitative real-time PCR (qPCR) including staining with propidium monoazide (PMA). It was determined, that DLC:Ag film was the most efficient coating in the reduction of C. jejuni and L. monocytogenes numbers. Culture-based enumeration revealed that C. jejuni numbers were reduced by an average of 4.06log10CFU/ml after 15min and 3.61log10CFU/ml after 30min on DLC:Ag coated silicon wafers in comparison to control samples (P≤0.05). L. monocytogenes was not detected on DLC:Ag samples after 24h of exposure (P≤0.05). PMA-qPCR showed that C. jejuni and L. monocytogenes affected by DLC:Ag antimicrobial surface showed a reduced ability to grow on culture media, but maintained viability during the whole experiment. Nonetheless, DLC:Ag antimicrobial surface could be further considered for the reduction of cross-contamination risk from food preparation surfaces due to their contamination with C. jejuni and L. monocytogenes in domestic and commercial kitchens or food establishments.

Effect of Ti content on structure and mechanical properties of Cr–Ti–N films

Cr–Ti–N films are deposited on the surface of Ti6Al4V alloy by unbalanced multi-targets reactive magnetron sputtering. In this study, the effect of the Ti content on microstructure, hardness, modulus and tribological behaviours of Cr–Ti–N films are systematically investigated. The XRD shows that with the increasing of Ti content, the phase structure evolves from Cr + Cr2N + TiN → amorphous → FCC solid solution. The hardness and modulus of Cr–Ti–N films are increased by improving Ti content in the films and Cr32.5Ti24.6N42.9 film reaches maximum values of 25.8 and 362.7 GPa, respectively. The wear rate of the Cr–Ti–N films is gradually decreased with increasing Ti content and the Cr32.5Ti24.6N42.9 film decreases five times and 25 times than Cr50.7Ti10.1N39.2 and substrate, respectively.

Effect of bias voltage on the properties of CeO2−x coatings prepared by magnetron sputtering

In this study, cerium oxide (CeO2−x) coatings were deposited onto silicon substrates by reactive unbalanced magnetron sputtering in an Ar-O2 gas mixture. The effect of substrate negative bias voltage on the surface morphology, wetting behavior, microstructure, mechanical and tribological properties of CeO2−x coatings were systematically investigated. It was found that the surface morphology and the root mean square (RMS) roughness of the coatings exhibited a non-linear evolution. The smoothest surface with a RMS roughness of about 3.3nm was obtained at a bias voltage of −60V. All deposited coatings exhibited a hydrophobic feature with the water contact angle around 100°, which was close to the value obtained from Teflon surface. X-ray diffraction (XRD) analyses revealed the best crystallinity of CeO2−x coatings in cubic CeO2 phase at a critical value of −80V bias. Cross-sectional scanning electron microscope (SEM) images displayed typical columnar-type structures with a relatively large column grain for the coating deposited at −20V and a dense, fine-grained microstructure obtained at −80V. The microstructure improvement at the optimized bias (−80V) contributed further to the enhancement in the hardness, reaching a maximum value of ~18.0GPa. The average friction coefficients of as-deposited coatings prepared between −40 and −120V were measured to be around ~0.40, whereas the coating prepared at −80V showed the best anti-wear performance. The wear volumes were two orders of magnitude lower than that of 316 stainless steel (SS) and three orders of magnitude lower than that of Teflon.