Effect Of Deposition Temperature Research Articles

Effect of substrate roughness and PVD deposition temperatures on hardness and wear performance of AlCrN-coated WC-Co

Elevated temperature experienced in the cutting zone is the main issue contributing to severe wear and responsible in reducing the lifespan of cutting tools'. This study aims to improve the performance of the cutting tool by applying AlCrN coating on the WC-Co substrate using physical vapor deposition (PVD). Prior to the coating process, the WC-Co surface was chemically roughened by Murakami's solution, followed by Caro's solution for 10s. The etched substrates were coated with AlCrN at various PVD deposition temperatures. The scanning electron microscopy (SEM) showed the coating thickness increased from 1.24 μm to 2.78 μm. X-ray diffraction (XRD) pattern confirmed that both AlN and CrN phases dominated the coating layer indicated the presence of AlCrN coating. These XRD peaks were broader, indicating a smaller grain size (11.5 nm) produced at higher deposition temperatures. Apart from that, a minute amount of the Cr2N phase is also detected. The average compressive residual stresses ranged from −5.409 GPa to −1.707 GPa attributed to increased coating thickness associated with Cr2N+N2 → CrN phase transformation. There are no cracking and coating delamination observed at this state. The mechanical properties of the coated structure were further evaluated via Vickers microhardness and linear reciprocating tests. The hardness obtained ranged from 600 to 1617 HV0.2. While the coefficient of friction (CoF) measured was 0.21 after 240 m of sliding distance. The calculated wear rate was 2.283×10−4 mm3/N·m which exhibited a significant reduction in wear when coated at 450 °C compared to 4.550×10−4 mm3/N·m at a lower temperature (250 °C). Therefore, it can be concluded that the effect of roughened substrate and various PVD deposition temperatures have significantly influenced the coating phase formation, which subsequently effects the hardness and wear performance of AlCrN-coated tungsten carbide.

Slot-die processed perovskite solar cells: effects of solvent and temperature on device performances

We studied the effects of perovskite precursor solvents and deposition temperatures on perovskite-layer formation for slot-die coating based solar cell fabrication. To select better solvent and temperature conditions, various representative polar solvents (dimethyl sulfoxide (DMSO), N-methyl-2-pyrrolidone, N,N-dimethylformamide (DMF), γ-butyrolactone) and various deposition temperatures (70 °C–150 °C), well-known as key conditions in conventional spin-coating systems, were studied and compared. Comparative studies revealed the DMSO:DMF (5:5) solvents and the 130 °C can provide better solar-cell performances with cell-efficiency up to 15.40% in slot-die based planar perovskite devices, demonstrating an advanced step for better-efficiency slot-die-coating based perovskite solar cells.

The effect of deposition temperature on microstructure and mechanical properties of SiC coatings on graphite

The effect of deposition temperature on microstructure and mechanical properties of SiC coatings on graphite

Effects of Deposition Potential and Temperature on Co(II) Reduction and Electrocrystallization for Preparing Nanocrystalline Co Coatings in Ethylene Glycol Solution

Based on cyclic voltammetry (CV) and chronoamperometry (CA) experiments, the effects of deposition potential and temperature on Co(II) reduction and electrocrystallization in ethylene glycol (EG) are reported. CV observations show that Co(II) reduction reaction is irreversible, and both the equilibrium potential and nucleation overpotential, η nucleation, move to more positive values as the temperature is improved. The diffusion coefficient of Co(II) is 2.24 × 10−6 cm2 s−1 at 323 K and the activation energy for bulk diffusion (E bd) of Co(II) is 22.03 ± 0.8 kJ mol−1. CA observations show that the Co electrocrystallization mechanism is a 3D nucleation and growth of a new phase under diffusion control. Its mechanism is an instantaneous regime at 323 K at various applied potentials, however, the mechanism changes from a progressive nucleation to an instantaneous nucleation at −1.10 V as the temperature increases. The cobalt nuclei are spherical microstructure, and these innumerable spherical crystal particles can align compactly to form many wirelike crystals bundles. XRD observation confirms the characteristic peak of crystalline Co with a preferred orientation direction and the average size of Co grains is 19 nm. It is also found that the Co coating thickness is affect by the potential and temperature.

Effects of deposition temperature on Mo/SiC Schottky contacts

We report on the results of our investigation of the effect of deposition temperature on molybdenum (Mo) used as Schottky contacts to fabricate silicon carbide (SiC) Schottky barrier diodes. The contacts were deposited using magnetron sputtering on n-type 4H-SiC at temperatures ranging from 25 to 900 °C. The fabricated diodes were characterized by current–voltage, current–voltage–temperature, and capacitance–voltage measurements. The diodes showed average Schottky barrier heights that decreased from 1.54 to 1.00 eV with increasing deposition temperature of the contacts. The average values of the ideality factors similarly decreased from 1.21 to 1.06 with increasing deposition temperature. However, the diodes with contacts deposited at 400–900 °C nearly maintained a constant ideality factor value of 1.06. The x-ray diffraction analysis indicated that silicides were formed at the interface for contacts deposited at or above 400 °C. The improved properties of the diodes with contacts deposited at higher temperatures are correlated with the formation of the interfacial alloys possessing improved electrical properties. This work demonstrates that high temperature deposition is another method for optimizing the properties of Mo contacts for the fabrication of 4H-SiC Schottky diodes for electronic applications in high power and high temperature environments.

The effects of doping and temperature on properties of electrochemically deposited Er3+ doped ZnSe thin films

Zinc Selenide (ZnSe) is a binary chalcogenide with band gap (Eg) of about 2.70 eV. Doping is used to tune band gap in order to optimize electrical and optical properties of thin films. The aim of this work was to determine the effects of doping and deposition temperature on the properties of erbium doped zinc selenide (Er3+;ZnSe). Undoped ZnSe and Er3+;ZnSe (1–4%)] were deposited at room temperature and at deposition temperatures between 40 °C and 100 °C on fluorine doped tin oxide (FTO) glass by electrochemical technique. The effects of doping and deposition temperature on the crystal structure, morphology, optical and electrical properties of the deposited ZnSe were investigated. XRD results showed that both undoped and Er3+;ZnSe were crystalline in nature with strong orientation along (111) and (311) directions. Peak intensity of Er3+;ZnSe decreased from Er1% to Er3% as doping concentration increased and then increased as concentration increased to 4%. The peaks were indexed to the cubic structure of ZnSe thin film with Er2% showing the highest purity. The UV–vis result revealed that the samples deposited at higher deposition temperatures [Er4%(80 °C) and Er4%(100 °C)] showed lower transmittance. Undoped ZnSe had band gap of 2.75 eV which approximated the bulk value. The band gap was observed to decrease as deposition temperature increased. The films deposited at room temperature had wider band gap (2.9 eV–2.61 eV) than those deposited above room temperature (2.21 eV–1.69 eV). The SEM micrograph revealed that low doping concentration (Er1%) had no effect on morphology. Er2% had the highest resistivity of about 8.41 × 103 Ωcm and lowest conductivity of 1.19 × 10−4 Ωcm−1. Doping and deposition temperature thus affected most of the investigated properties. Er3+;ZnSe (Er1% - Er4%) and Er4% (40 °C) – Er4% (100 °C) find applications as solar cell buffer layers and absorbers respectively.

Effects of Deposition Temperature on the Microstructure, Mechanical Properties, High Temperature Corrosion and Oxidation Properties of Alcrnbtizr High Entropy Alloy Coatings

Effects of Deposition Temperature on the Microstructure, Mechanical Properties, High Temperature Corrosion and Oxidation Properties of Alcrnbtizr High Entropy Alloy Coatings

Spatial atmospheric pressure molecular layer deposition of alucone films using dimethylaluminum isopropoxide as the precursor.

Trimethylaluminum is the most used aluminum precursor in atomic and molecular layer deposition (ALD/MLD). It provides high growth-per-cycle (GPC), is highly reactive and is relatively low cost. However, in the deposition of hybrid alucone films, TMA tends to infiltrate into the films requiring very long purge steps and thereby limiting the deposition rate (nm s-1) of the process. From our previous studies, we know that dimethylaluminum isopropoxide (DMAI) could be a potential candidate to substitute TMA in alucone depositions as it does not seem to infiltrate into the films. In this study, we perform a more detailed investigation of MLD of alucone on an atmospheric pressure spatial MLD system using DMAI as the aluminum precursor. The effect of deposition temperature and reactant purge times on the overall GPC has been investigated and a decreasing GPC with increasing deposition temperature and increasing EG purge time has been observed. Furthermore, the DMAI alucone films have been compared for their chemical environment and degradation with the films prepared using TMA and EG, showing striking similarities between the two. The results demonstrate that DMAI can be used as an alternative precursor to TMA for MLD of alucone films and this work can be used as a guide for designing efficient MLD processes in the future.

Effect of Deposition Temperature on the High-Temperature Corrosion Resistance of Crmonbzr High-Entropy Alloys Coatings

Effect of Deposition Temperature on the High-Temperature Corrosion Resistance of Crmonbzr High-Entropy Alloys Coatings

Effects of Deposition Temperature and Metal Electrode on Ferroelectric Properties of Atomic-Layer-Deposited Hf0.5zr0.5o2 Film

Effects of Deposition Temperature and Metal Electrode on Ferroelectric Properties of Atomic-Layer-Deposited Hf0.5zr0.5o2 Film

Deposition temperature effect on sputtered hydroxyapatite coatings prepared on AZ31B alloy substrate

The corrosion of Mg alloys is a provocative topic and it is still a challenge to find a solution for the improvement of their degradation rate into solution found in human body (Simulated Body Fluid, SBF). The aim of the present paper is to coat AZ31B alloy by hydroxyapatite (HAp) as a possible solution in order to change its degradation behaviour for medical implants. Since the Mg alloy is sensible to temperature while the HAp properties depend on the deposition temperature, in this study, the effect of deposition temperature on the properties of the AZ31Balloy was evaluated. The HAp coatings were prepared using the RF magnetron sputtering technique, ranging the temperature from the room one to 400 °C. It was found that the grain size of the investigated Mg alloy increased more than 100% when the deposition temperature was increased. By increasing the temperature, the hardness level was reduced of about 15%. All HAp coatings revealed corrosion behaviour much better than the uncoated AZ31B alloy; in particular, the coating deposited at 200 °C exhibited the best corrosion behavior. Moreover, the best protection to the corrosive attack of SBF was found for the HAp coating deposited at 200 °C (97.3%), which was also characterized by the lowest porosity. To conclude, HAp coatings can be used to improve the properties of AZ31B alloys, but just up to 200 °C; beyond this temperature, the mechanical and the anticorrosion properties are lost.

Study on effect of deposition temperature on photoelectrocatalyatic performance of immobilized TiO2

This work reports the preparation of polycrystalline titanium dioxide (TiO2) thin films using spray pyrolysis technique at various temperatures to access their photoelectrocatalytic (PEC) performance. The films were characterized by photocurrent response measurements, X-ray diffraction, Scanning electron microscopy, Elemental analysis, Fourier-transform Raman spectroscopy and UV–vis spectroscopy. The TiO2 showed heterogeneous photocatalytic potential against the oxidative degradation of Phthalic acid (PA) and Benzoic acid (BA) which were used as model pollutants. The PEC behavior of the typical TiO2 film was excellent for oxidative degradation of both pollutants under UV irradiation.

Effects of deposition temperature on structure, residual stress and corrosion behavior of Cr/TiN/Ti/TiN films

Composite TiN film was prepared on AZ31 at four sets of different deposition temperatures. X-ray diffraction and X-ray fluorescent were employed to determine the structure, residual stress, thickness and chemical elements. A scratch tester with Rockwell C diamond styli and electrochemical workstation were used to evaluate the adhesion and corrosion behavior of the obtained film. The effects of deposition temperature on structure, residual stress, adhesion, thickness and corrosion behavior were investigated as well. The results show that the films are composed of TiN with (111), (200) and (222) planes, Ti with (002) plane, and Cr (110) plane. The maximum residual compressive stress is about 413.4 MPa, and the elements distribution is not uniform when the film deposited at 150 °C. With the increase of deposition temperature, the grain size and crystallinity increase, the thickness decreases, the residual stress decreases first and then increases, the film becomes more compact and has better corrosion resistance. However, when the deposition temperature is greater than 250 °C, the surface roughness and the thermal stress begin to increase, the bonding performance and the corrosion resistance also decrease.

Microstructural, linear and nonlinear optical study of spray pyrolysed nanostructured La–ZnO thin film: An effect of deposition temperature

Transparent Zn0.97La0.03O nanostructures were prepared at different temperatures (300 °C–500 °C) on borosilicate glass substrates using the chemical spray method. The present work focused on the dependence of the substrate temperature (Ts) on the different characteristics of the prepared films. In all the deposits, a polycrystalline structure of La3+ doped ZnO (LZO) film with a preferred orientation along the (101) plane was observed, and a larger crystalline size was noticed for films deposited at lower temperatures. The surface morphology changed from spherical to fibrous structure as a function of the temperature of the substrate. The chemical state and elemental compositions were confirmed by XPS analysis. The linear optical band gap and third-order nonlinear absorption coefficient of LZO films were observed to increase with an increase in substrate temperature. A maximum transmittance was observed for the sample prepared at 450 °C with the least optical limiting threshold value of 0.96 kJ/cm2. The presence of various defects in the film was confirmed through photoluminescence emission, and red emission was noticed for samples prepared at 450 °C and 500 °C.

LaPO4 coating on alumina-based fiber: Strength retention of fiber and improvement of interfacial performances

The characteristics of the interface are the key factors that determine the mechanical properties and fracture behavior of fiber-reinforced ceramic matrix composites. Design and preparation of coatings which can preserve fiber strength and maintain appropriate interfacial bonding strength are of great challenges. LaPO4 coating is a promising weak interface coating for oxide fiber reinforced oxide ceramic matrix composites. Through this coating, the toughening mechanism of the composite such as fiber pulling out and fiber debonding is triggered. The LaPO4 coating was deposited on the surface of alumina-based fibers by a solution precursor heterogeneous precipitation method. The effects of different precursors and different deposition temperatures on fiber strength were studied, and the mechanism of the strength degradation of the coated fiber was analyzed. It was found that the fibers coated with phytic acid precursor and deposited at 90 °C had the highest tensile strength compared to other coated fibers. The retention of strength is attributed to its loosely stacked coating. Besides, a single fiber pullout test was carried out to evaluate the effect of the coating on the interface of the composites. The results show that the composites coated by depositing citric acid precursor and phytic acid precursor at 90 °C can reduce the interfacial bonding strength by 32.5% and 46.7%, respectively compared to uncoated composites. This study has potential application value in the preparation of ceramic matrix composites used in oxidation and high temperature environments.

Electrical Characteristics and Reliability of SiCN/Porous SiOCH Stacked Dielectric: Effects of Deposition Temperature of SiCN Film

Silicon carbonitride (SiCN) films deposited using silazane singe-precursor with different temperatures were capped onto porous carbon-doped silicon oxide (p-SiOCH) dielectric films. Effects on the electrical and reliability characteristics of the fabricated SiCN/p-SiOCH stacked dielectrics were investigated. Experimental results indicated that increasing the deposition temperature of the SiCN film increased barrier capacity against Cu migration under thermal and electrical stress and time-dependence-dielectric-breakdown reliability for the SiCN/p-SiOCH stacked dielectric. Therefore, this study provides a promising processing to deposit a SiCN barrier by elevating the deposition temperature and using N-methyl-aza-2,2,4-trimethylsilacyclopentane singe-precursor, which can be applied to back-end-of-line interconnects for advanced technological nodes in the semiconductor industry. A larger capacitance, however, is the main issue due to a larger intrinsic dielectric constant of the SiCN film and stronger plasma-induced damage on the p-SiOCH film. As a result, the related actions will be taken in the future research to improve this issue.

Effect of residual impurities on polarization switching kinetics in atomic-layer-deposited ferroelectric Hf0.5Zr0.5O2 thin films

The ferroelectricity in fluorite-structured ferroelectrics such as HfO2 and ZrO2 has attracted increasing interest in both academia and industry. Although the polarization switching kinetics is one of the research topics which critically requires further study for the novel ferroelectric material, various factors affecting the polarization switching kinetics have not been rarely examined to date. Especially in atomic-layer-deposited films, the defects including residual impurities are expected to strongly influence the polarization switching kinetics. In this study, therefore, the effect of deposition temperature (Tdep) and impurity concentration on the physical/electrical properties and polarization switching kinetics of atomic-layer-deposited Hf0.5Zr0.5O2 thin films is reported based on physical/chemical/electrical analyses. With decreasing Tdep, the concentration of residual impurities, including carbon increased, resulting in decreased grain size. The increased defect concentration decreased the median switching time and increased the deviation of the switching time distribution. This can be attributed to the lowered energy barrier for the nucleation of oppositely polarized domains and increased spatial inhomogeneities, respectively. This result suggests that Tdep is a key process parameter for optimizing the polarization reversal behavior of fluorite-structured ferroelectrics as it has a considerable influence on the ferroelectric properties and polarization switching kinetics, which are strongly correlated to the defect concentrations and microstructure.

Low-Pressure CVD of GeE (E = Te, Se, S) Thin Films from Alkylgermanium Chalcogenolate Precursors and Effect of Deposition Temperature on the Thermoelectric Performance of GeTe.

The homologous series [GenBu3(EnBu)] (E = Te, Se, S; (1), (3) and (4)) and [GenBu2(TenBu)2] (2) have been synthesized as mobile oils in excellent yield (72-93%) and evaluated as single-source precursors for the low-pressure chemical vapor deposition (LPCVD) of GeE thin films on silica. Compositional and structural characterizations of the deposits have been performed by grazing-incidence X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray analysis, and Raman spectroscopy, confirming the phase purity and stoichiometry. Electrical characterization via variable-temperature Hall effect measurements is also reported. Given the strong interest in GeTe and its alloys for thermoelectric applications, variable-temperature Seebeck data were also investigated for a series of p-type GeTe films. The data show that it is possible to tune the thermoelectric response through intrinsic Ge vacancy regulation by varying the deposition temperature, with the highest power factor (40 μW/K2cm@629 K) and effective ZT values observed for the films deposited at higher temperatures.

Comparative analysis of the effect of annealing temperature on the structural and optical properties of chemically deposited CeO2/ZnO and CeO2/NiO core-shell thin films for photovoltaic and optoelectronic applications

This paper describes the deposition and characterization of CeO2/ZnO and CeO2/NiO coreshell thin films with emphasis on the effect of post deposition temperature on the optical properties and structural patterns. The structural temperature-dependent analysis indicated different XRD patterns for both films. However, both films are polycrystalline as depicted by the various peaks in the XRD diffractograms. The SEM images for both films differ in terms of their particle aggregation and distribution. The dependence of the transmittance, absorption coefficient, band gap, refractive index, extinction coefficient, imaginary dielectric constant on annealing temperature were investigated. The results showed that the transmittances of the films were significantly reduced by the heat treatments. The transmittance reduced from 92% to 65% for CeO2/ZnO film samples and 63% to 30% for CeO2/NiO film samples. The band gap showed considerable variation with annealing temperatures. The band gaps of all samples were in ranges of 1.75–3.85 eV and 3.50- 3.88eV for CeO2/ZnO and CeO2/NiO core-shell thin films respectively. The values of the energy band gap strongly indicate that the films can be used in different optoelectronic applications including solar photovoltaic.

Optical properties of anatase and rutile TiO2 films deposited by using a pulsed laser.

Transparent titanium dioxide (TiO2) films were deposited on quartz substrates by using a pulsed-laser deposition technique. The effects of deposition temperatures on the crystalline phases and optical properties of the films were investigated. Phase-pure anatase and rutile TiO2 films were obtained at temperatures of 600°C and 800°C, respectively. The deposited TiO2 films were transparent in the visible spectral region, and the linear refractive indices of the films were determined by using the optical transmission spectra. The optical bandgaps were obtained as 3.25 and 3.02 eV for the anatase and rutile TiO2 films, respectively. The third-order nonlinear optical properties of the films were investigated by using a single-beam z-scan method at a wavelength of 532 nm. The values of the nonlinear absorption coefficient and the nonlinear refractive index of the rutile TiO2 film were determined to be -7.44×10-10m/W and -1.36×10-16m2/W, respectively, which are greater than those of the anatase TiO2 film. The metal-oxygen bond lengths based on the bond-orbital theory could be used to explain the results.