Influence Of Deposition Rate Research Articles

Martensitic ternary FeCrMn thin films sputtered from austenitic AISI 202 stainless steel target: Phase transition and corresponding magnetic properties under the influence of deposition rate

The nanostructured materials exhibit quite different properties from their bulk counterparts. Therefore, in this work, phase transition from a commercial austenitic AISI 202 (Bulk FeCrMn) stainless steel to martensitic ternary FeCrMn thin films under variation of deposition rate were studied. The films were easily sputtered onto a flexible amorphous polymer substrate from the target by a DC magnetron. X-ray diffraction analysis showed that austenitic phase of the target converted into a mixture of martensitic and a very weak of austenitic phase of the films at the deposition rates of 0.04 and 0.06 nm/s. With a further increase of the deposition rate, martensitic phase in the films increased, and at the highest deposition rate, the film with 100 % martensite phase was obtained. According to magnetic analysis, austenitic target consists of paramagnetic and ferromagnetic components as oppose to the paramagnetic phase stated in the literature. The films obtained by sputtering of austenitic target have ferromagnetic character with an increasing saturation magnetization, MS as the deposition rate increases. The increase of the MS from 117 to 346 emu.cm−3 may be explained by the increase of the % martensite that may increase the ferromagnetic character. Also, the increase of the coercivity of the films from 31 to 196 Oe may have come from the increase of % martensite and the increase of grain sizes with increasing deposition rates which may induce the stress in the films. It is seen that the nanostructured ternary FeCrMn thin films exhibit quite different phase and corresponding magnetic properties from their bulk counterpart. With sputtering, martensitic phase transition of ternary FeCrMn thin films can be controlled by varying deposition rates. It presents a potential usage for data storage and micro electric-electronic devices on flexible substrates.

Laser-induced alloy nanoparticles: Au–Sn thin film morphology influence on the dewetting process

In this paper, the impact of thin Au–Sn layers morphology on the formation of laser-induced alloy nanoparticles (ANPs) is investigated. Also, the changes in composition observed over time in thin films are analysed. The influence of deposition rate and elemental composition was studied. The tests were performed on five sets of samples of varying atomic ratios of Au–Sn and film thickness, for which the optical parameters were measured with the spectroscopic ellipsometry technique (SE). The samples were dewetted with a nanosecond Yb:glass fibre laser. All fabricated surfaces were analysed using scanning electron microscopy (SEM). Moreover, the chemical composition of obtained structures was analysed using X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM).

Influence of deposition rates on the mode I fracture toughness of in-situ consolidated thermoplastic composites

Innovations in recycling, automated and out-of-autoclave processes have renewed significant interests in carbon fibre - polyether ether ketone (CF/PEEK) thermoplastic composites. The crystallinity and, consequently, fracture toughness of semi-crystalline thermoplastics is affected by the cooling rates during processing. Extensive review of published data indicates that in-situ consolidation deposition rates affect PEEK crystallisation. This paper investigates the influence of automated fibre placement (AFP) deposition rates from 76 to 124 mm/s on the crystallinity and mode I fracture toughness of Cytec PEEK polymer matrix with carbon Fibre (AS4/APC2) laminates. The experimental results showed a decrease in crystallinity when the material deposition rate was increased. However, this did not translate into an improvement in fracture toughness. The preliminary study showed an increase in fracture toughness from 76 to 100 mm/s deposition rates. The 124 mm/s samples had the lowest fracture toughness despite having the lowest crystallinity. The crystallinity was not the only driving mechanism in improving the fracture toughness performance and good consolidation is an important factor as well.

Easy Controlled Properties of Quaternary FeNiCrCd Thin Films Deposited from a Single dc Magnetron Sputtering Under the Influence of Deposition Rate

The quaternary FeNiCrCd thin films were produced from a single FeNiCrCr source on a commercial flexible polymer substrate using one dc magnetron sputtering technique. For that, a series of the films with a thickness of 50 nm were produced at different deposition rates of 0.02, 0.04, 0.06, and 0.08 nm/s, separately. In this study, as far as concerned, this was the first time that structural and magnetic properties of FeNiCrCd thin films were investigated. According to compositional analysis, the Fe and Cr contents slightly decreased with increasing deposition rate while Ni was almost constant, whereas those of the amount of Cd atoms increased. However, the atomic amounts of Fe and Cd in the films are quite different from those of the source material. The change of the atomic contents in the films from the source may be attributed to the relatively different bond energy/melting point of metals which have different contents sputtered from source material since this physical parameter is very significant for the sputtering process. For crystal structural analysis, a combination of hexagonal close-packed (hcp) and body-centered cubic (bcc) were observed. The peak intensity of the bcc-dominated planes decreased while the hcp-dominant plane increased since the change in peak intensities is compatible with the compositional analysis with increasing deposition rate. And, the grain sizes decreased gradually from 40.1 to 23.4 nm, with increasing deposition rate from 0.02, to 0.08 nm/s. Also, the film surfaces transformed from a rough to smooth surfaces with decreasing grain sizes as deposition rate increased. For magnetic analysis, the saturation magnetization Ms values decreased as 1030, 773, 730, and 217 emu/cm3 with increasing deposition rate as 0.02, 0.04, 0.06, and 0.08 nm/s, respectively. In the same manner, the coercivity Hc values were found as 11, 7, 6, and 2 Oe with the deposition rate of 0.02, 0.04, 0.06, and 0.08 nm/s, respectively. The decrease of the Hc may have primarily come from the transformation of rough to smooth surface of the films. It may also be said that the films showed soft magnetic properties due to their low Hc values with increasing deposition rate. Thus, the magnetic properties of the quaternary FeNiCrCd alloy films were seen to be easily improved with the deposition rate parameter for potential use in different industrial applications.

Influence of deposition rate on the structural, optical and electrical properties of electron beam evaporated SnO2 thin films for transparent conducting electrode applications

The role of deposition rate in the structural, optical and electrical properties of SnO2 thin films deposited by electron beam evaporation method is investigated by varying the deposition powers viz. 50, 75, and 100 W. The structural characterization of the films is done by X-ray diffraction (XRD) technique. The surface morphology of the films is studied by scanning electron microscopy (SEM). Rutherford back scattering (RBS) measurements revealed the thickness of the films ranging from 200 nm to 400 and also a change in the concentration of oxygen vacancies which is found to be the maximum in the film deposited at the lowest deposition rate. Optical absorption spectrum is recorded using the UV–V is spectroscopy and the films are found to be transparent in nature. A shift in the absorption edge is observed and is attributed to a different level of allowed energy states in conduction band minimum. The Hall effect and electrical measurements show a variation in the carrier concentrations, mobility and resistivity of the films. In order to explore a better compromise in electrical and optical properties for transparent electrode applications, skin depths calculations are also done to find the optimized values of carrier concentration and mobility.

The Influence of Deposition Rates on Properties of AlPcCl Thin Films and on the Performance of Planar Organic Solar Cells

The performance of organic photovoltaic cells depends on different properties of the organic materials, such as carrier mobility, band structure, morphology, and crystallinity. For AlPcCl, it is shown that these properties are dependent on the layer deposition rates. As the deposition rate increases, the surface roughness of AlPcCl layers decreases. In contrast, the crystallinity of the layers increases as the deposition rate decreases, thereby increasing the hole mobility value. These effects are opposed: the former effect allows higher open circuit voltages to be obtained as the deposition rate increases, whereas the latter increases the short circuit current as the deposition rate decreases. Therefore, there is a trade‐off between open and short circuit current values, and it is necessary to find the best deposition rate for AlPcCl. Here, it is shown that the highest mobility carriers in layers deposited slowly allow the use of thicker AlPcCl layers, which permits acceptable open circuit voltage values and optimum photovoltaic cell efficiencies to be obtained. This results in an optimum efficiency value of 3.97% for a 26‐nm‐thick AlPcCl film that is deposited at 0.02–0.03 nm s−1.

The structural and electrical properties of samarium doped ceria films formed by e-beam deposition technique

Sm2O3-doped CeO2 (Sm0.15Ce0.85O1.925, SDC) thin films were formed by e-beam evaporation method. Thin films were formed evaporating micro powders (particle size varied from 0.3 to 0.5μm). The influence of deposition rate on formed thin film structures and surface morphology were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersion spectrometry (EDS), and atomic force microscopy (AFM). The deposition rate of formed SDC thin films was changed from 2 to 16Å/s. The electrical properties were investigated as a function of frequency (0.1–106Hz) at different temperatures (473–873K).The formed SDC thin ceramic films repeat the crystallographic orientation of the initial powders using different substrates and different deposition rate. It was determined that crystallites size and samarium concentration are decreasing by increasing the deposition rate. The crystallites size decreased from 17.0nm to 10.4nm when SDC thin films were deposited on Alloy 600 (Fe-Ni-Cr), and decreased from 13.7nm to 8.9nm when were used optical quartz substrate.The best ionic conductivity σtot=1.66Sm−1 at 873K temperature, activation energy ΔEa=0.87eV (σg=1.66Sm−1, σgb=1.66Sm−1) was achieved when 2Å/s deposition rate was used. The grain size (in the formed SDC thin films) was ~83nm in this case.

Influence of aluminum content on plasmonic behavior of Mg-Al alloy thin films

The influences of deposition rate and alloying with aluminum (0 to 65 at.%) on the structure and optical properties of magnesium films on quartz are examined. Results show that increasing the deposition rate improves the plasmonic figure of merit (FOM) values, and decreases the surface roughness and grain size. Addition of Al to Mg blue shifts the localized surface plasmon (LSP) figure of merit peak position and improves LSP FOM values over portions of the ultraviolet (UV) region. Nanotriangles (NTs) of Mg and Mg-Al on quartz were fabricated using colloidal lithography. Mg-Al NTs show improved LSP resonance (LSPR) response compared to Mg particles due to improved structural integrity.

Influence of deposition rate and substrate temperature on structure and optical features of NiO thin film

Influence of deposition rate and substrate temperature on structure and optical features of NiO thin film

The Influence of Deposition Rate on the Structure and Morphology of Gold/Silicon(111) Growth by Molecular Beam Epitaxy

ABSTRACTThe effect of deposition rate on the structural and morphological properties of thin gold films is reported with characterization by scanning tunneling microscopy and X-ray diffraction. The epitaxial growth of Au films on Si(111) 7 × 7 substrates was performed by molecular beam epitaxy under ultrahigh vacuum. The changes in the morphological properties of deposited films were monitored when the deposition rate was varied from 0.15 to 4.3 nm/min. The crystallographic structure of the films was assessed by X-ray diffraction. The grain size increased with the deposition rate and reached a maximum of 112.5 nm at 1.6 nm/min. At higher deposition rates, the grain size and the lattice strain slightly decreased. The flatness of the films was assessed by scanning tunneling microscopy under ultrahigh vacuum at room temperature. At the optimal deposition rate of 1.6 nm/min, the film was very smooth (0.02 nm). At lower or higher deposition rates, the roughness was increased. These results show that the quality of the film strongly depended on this parameter. The optimal roughness, thickness, and grain size occurred at a deposition rate of 1.6 nm/min.

Influence of deposition rate on PL spectrum and surface morphology of ZnO nanolayers deposited on Si (100) substrate

Zinc oxide (ZnO) thin films were deposited on Si (100) substrate through sputtering of zinc by DC magnetron, followed by thermal oxidation. Different deposition rates were used in coating films with 100 nm thickness (0·6–4·5 nm/s). Photoluminescence spectra of the produced samples were obtained and it was found that the violet emission peak intensity increases with deposition rate. Scanning electron microscopy (SEM) micrograph and atomic force microscopy (AFM) images for the zinc oxide films were obtained. Morphological changes due to various deposition rate are discussed in the light of changes observed in the ZnO crystals. Low coating rates produced smooth surface with small grains while higher deposition rates increased the surface roughness and larger grain size. AFM and SEM results are in good agreement and support the PL results.

Low coverage Si(111)√7×√3–In reconstruction: Deposition rate effect

Abstract Si(1 1 1)–In surface reconstructions for submonolayer coverages were investigated at room temperature using X-ray photoelectron spectroscopy, Auger electron spectroscopy and low-energy electron diffraction. Deposition rate influence on the formation of surface structures is reported. It was observed that for sufficiently low deposition rate and certain annealing process Si(1 1 1)√7 × √3–In surface reconstruction at coverage as low as 0.2 ML is present.

Characterization of TiO<sub>2</sub> Thin Films Prepared by Vacuum Evaporation

The TiO2 thin films were prepared by vacuum evaporation on glass using TiO2 powder 99.99% as coating material and with varying deposition speed. The TiO2 thin films were characterized by a-step device, X-ray diffraction (XRD), atomic force microscope (AFM). The influence of deposition rate were discussed. The results indicated that thickness of the TiO2 thin film was prepared under the deposition rate of 4Å/sec was 200 nm at room temperature, with amorphous structure. The film changed to anatase crystal structure when was annealed at 450 °C for one hour and the TiO2 thin film was uniform and well combined with the glass substrate.

Influence of Deposition Rate on Optical Properties of RF-Magnetron Sputtered Carbon–Nickel Composite Films Deposited at Different Deposition Times

In this work, the optical properties of carbon–nickel films deposited at different deposition times from 50 to 600 sec were investigated. Reflectance measurements in wavelength range 300–1000 nm were used to compute the refractive index and optical dispersion parameters according to Wemple and DiDomenico single oscillator model (WDD). Dispersion curves of the refractive index of films show anomalous dispersion in absorption region and normal dispersion in transparent region. It is shown that dissipative rate of the electromagnetic wave at 180 sec has a maximum value. It is also shown that at 180 sec films become more disordered.

Influences of deposition rate in second stage on the Cu(In,Ga)Se2 thin film and device prepared by low-temperature process

Polycrystalline Cu(In,Ga)Se2 (CIGS) thin ?lms are deposited onto soda-lime glass substrates by the low-temperature three-stage process (below substrate temperature of 420℃). The influences of growth rate in the second stage on structural and electrical properties of CIGS thin film and device performance are investigated. With the increase of deposition rate during the second stage, the crystallinity and grain compactness of CIGS thin film are promoted, and the double-peak reflection pattern is reduced obviously,which can reduce the recombination in the grain boundary and help to improve the conversion efficiency of the CIGS solar cell significantly. However, according to the experimental results, higher growth rate during the second stage leads to rough surface and low carrier concentration. The larger surface roughness can be attributed to the larger grain size of secondary-phase Cu2-xSe, and the lower carrier concentration results from the reduction of passivation donor defect effect which is induced by the hindrance of Na diffusion from the glass substrate. High growth rate in the second stage is found to be able to increase the interface recombination and induce shunt paths in the solar cell and then the open circuit voltage and the cell parameters are deteriorated. Finally, a high conversion efficiency of 11.24% is achieved by optimizing the growth rate in the second stage.

Three-dimensional porous graphene-based composite materials: electrochemical synthesis and application

A general method for the fabrication of three-dimensional (3D) porous graphene-based composite materials is reported. This method involves two consecutive electrochemical steps. Firstly, 3D graphene (ERGO) porous material is prepared electrochemically by reducing a concentrated graphene oxide dispersion. Subsequently, the second component is electrochemically deposited onto this 3D ERGO matrix, yielding graphene-based 3D porous composite material. The prepared graphene-based composite materials have a conductive graphene network as the matrix, onto which the second component is homogeneously coated. Conducting polymers, noble metal nanoparticles and metal oxide were successfully incorporated into ERGO architectures, demonstrating the versatility of this method. Taking the ERGO–polyaniline composite as an example, the influence of deposition rate on the morphology of the composite was investigated. Finally, the application of the composite materials prepared with our method was discussed. The high surface area and low electrolyte transport resistance make these electrosynthesized composites suitable electrode materials for electrochemical devices. The ERGO–polyaniline composite electrode showed a high specific capacitance of 716 F g−1 at 0.47 A g−1, and this capacitance could be maintained at 502 F g−1 as the discharge current density was increased up to 4.2 A g−1.

Study on crystalline to amorphous structure transition of Cr coatings by magnetron sputtering

The influence of deposition rate on crystalline to amorphous microstructure transition of Cr coatings was studied through preparation of Cr coatings deposited onto silicon wafers using magnetron sputtering technique. The microstructure and morphology of Cr coatings were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and transmission electron microscopy (TEM). Results show that Cr coating prepared at 400W exhibits dense columnar crystalline structure and the crystallite size and crystallization rate are increased expressly in the initial 5min. When the deposition rate achieved to the maximum, Cr coating shows a case of infinite periodic renucleation where new crystals are assumed to be nucleated periodically on the surfaces of growing crystals and strong persistence of the columnar growth morphology is apparent. However, Cr coating exhibits overall microstructure of amorphous phase mixed with a few nano-crystal grains as the deposition rate decreases to the minimum.

Study of Stress in TiO<sub>2</sub> Films Grown by Electron-Beam Evaporation

TiO2 films were fabricated on Si substrate by using electron-beam gun evaporation. Influence of deposition rate, deposition temperature and ion beam bombarding on stress in TiO2 films was studied by AFM and XRD. The results show that deposition temperature of 423K and deposition rate of 0.2nm/s, the average stress in titanium oxide thin films is less than 48.2MPa. The average stress decreases to compressive stress of 16.7MPa from tensile stress of 72.9MPa by the ion beam energy of 113eV and bombarding time of 300s. The microstructure change of TiO2 films is main factors of stress development.

The influence of deposition rate on the stress and microstructure of AlN films deposited from a filtered cathodic vacuum arc

Aluminium nitride (AlN) thin films have been reactively deposited using a filtered cathodic vacuum arc system. A pulsed substrate bias was applied in order to increase the average energy of the depositing species. The stress and microstructure of the films were determined as a function of the deposition rate and pulse bias amplitude/frequency. The stress generated in films grown with high voltage pulsed bias depended on the deposition rate and a transition from tensile stress to compressive stress occurred as the deposition rate increased. This trend was accompanied by progressive changes in the microstructure. In order of increasing deposition rate, the films exhibited: a porous structure with tensile stress; a dense AlN film with compressive stress; and a dense AlN film showing evidence of a thermally induced reduction in stress.

Effect of Ion Beam Bombarding on Stress in TiO2 Thin Films

TiO2 films were fabricated on Si substrate by using electron-beam gun evaporation. Influence of deposition rate, deposition temperature and ion beam bombarding on stress in TiO2 films was studied by AFM. The results show that deposition temperature of 423K and deposition rate of 0.2nm/s, the average stress in TiO2 thin films is less than 48.2MPa. The average stress decreases to compressive stress of 16.7MPa from tensile stress of 72.9MPa by the ion beam energy of 113eV and bombarding time of 300s.