Physical Properties Of Films Research Articles

Nanoindenter를 이용한 W-C-N 박막의 신뢰도 측정과 열적 안정성 연구

이 논문에서는 반도체의 기판으로 사용되는 Si(silicon)기판과 금속배선 물질인 Cu(copper)의 확산을 효과적으로 방지하기 위한 W(Tungsten)-C(Carbon)-N(Nitrogen) 확산방지막을 제시하였고, 시료 증착을 위하여 rf magnetron sputter를 사용하여 동일한 증착조건에서 질소(N)의 비율을 다르게 증착한 후 시료의 열적 안정성 측정을 위하여 상온에서 <TEX>$800^{\circ}C$</TEX>까지 각각 질소 분위기에서 30분간 열처리 과정을 실시하여 열적 손상을 인가하였다. 이후 Nanoindentation 기법을 이용하여 총 16 points에서 Elastic modulus와 Weibull distribution을 측정하였다. 그 결과 질화물질이 고온에서 물성변화가 적게 나타나는 것을 알 수 있었고, 온도변화에 따른 박막의 균일도와 결정성 또한 질화물질에서 더 안정적이었다. In this paper, we deposited the tungsten carbon nitride (W-C-N; nitrogen gas flow of 2 sccm) and tungsten carbon (W-C) thin film on silicon substrate using rf magnetron sputter. Then the thin films annealed at <TEX>$800^{\circ}C$</TEX> during 30 minute (<TEX>$N_2$</TEX> gas ambient) for thermal damage. Nano-indenter was executed 16 points on thin film surface to measure the thermal stability, and we also propose the elastic modulus and the Weibull distribution, respectively. This nanotribology method provides statistically reliable information. From these results, the W-C-N thin film included nitrogen gas flow is more stable for film uniformities, physical properties and crystallinities than that of not included nitrogen gas flow.

A detachable SERS active cellulose film: a minimally invasive approach to the study of painting lakes

AbstractThe design and synthesis of a tailor‐made surface‐enhanced Raman scattering (SERS) active film that is fabricated to be removable from the surface of an artwork under study following effective measurements is detailed. It is shown that silver nanoparticles prepared by green chemical reduction with glucose can be effectively doped into a methylcellulose (MC) matrix for the formation of a gel, which can be subsequently applied to a minute area (ca 1–1.5 mm) of an artwork without posing a threat to its integrity. Studies have been aimed at characterizing this film's chemical and physical properties, with regard to the stability of the nanoparticles dispersed within the MC, the ease of application of the viscous gel, its speed of drying and the transparency of the dry film for SERS measurements. Importantly, results have led to reproducible SERS enhancements of the order 103–104 for studies carried out on reference laboratory dye components and unvarnished mock‐paintings. Techniques including optical and scanning electron microscopy were used to monitor the drying of the film and its resulting morphology, as well as to map the distribution of silver nanoparticles in the film so as to account for any visual modification to the underlying surface upon film removal. Copyright © 2011 John Wiley &amp; Sons, Ltd.

Physical properties of biaxially oriented PA6 film for simultaneous stretching and sequential processing

Abstract There are two different stretching processes that produce the biaxially oriented film, namely the tenter process and double bubble tubular film process. Furthermore, there are two tenter processes, i.e., the sequential biaxial stretching process and simultaneous biaxial stretching process. There is no report describing the difference among film physical properties of the three different processes. The biaxially oriented polyamide film using the double bubble tubular process has good balanced physical property and high impact strength, thus it is used for proper applications utilizing their advantage properties. In this report, the influence of each biaxial stretching process on film physical properties of polyamide, which has hydrogen bond, was studied in detail. As a result, the tentering process film has anisotropic tensile properties between machine direction (MD) and transverse direction (TD). This result was influenced by a later stretching process, namely TD stretching. On the contrary, the double bubble tubular film has good balanced properties, especially thermal shrinkage and impact strength. Tentering simultaneous stretching film has much larger shrinkage in MD than in TD. The sequential stretching film has larger shrinkage in TD than in MD. The double bubble tubular film has high impact strength, because it corresponds to the balanced molecular orientation.

RF sputtering of ZnO films in Ar and Ar–H2 gas mixtures: Role of H incorporation in developing transparent conductive coatings

Fundamental and applied investigation of ZnO has been recently experiencing a renaissance due to its prospective use in various technological domains and, in particular, as transparent conductive oxide (TCO). In this respect, the present work aims to study the structural and physical properties of ZnO thin films deposited by RF sputtering in pure Ar and Ar–H2 plasmas, at various concentrations (0–50%). The plasma chemical species were followed in function of the different gas mixture settings by optical emission spectroscopy (OES). X-ray photoelectron spectroscopy (XPS) and ATR-FTIR (Attenuated Total Reflection Fourier-Transformed Infrared) spectroscopy were used to study the bulk and surface chemical composition of the films, X-ray Diffraction (XRD) analysis allowed lattice structure and grain size determination while samples morphology was checked with a scanning electron microscope (SEM). The films were also characterized for their electrical and optical properties.The introduction of hydrogen in the plasma phase strongly affected the structural, chemical and physical properties of the films. In particular a pronounced change in the film electrical behavior was observed which become conductive when H is added in the gas mixture ([H2]>6%). The film transparency was on the other hand maintained. By combining XPS, ATR-FTIR and OES data we could correlate the established conductivity and its variations with intentional hydrogen incorporation in the crystal structure in the form of hydroxide species.

Development and characterisation of a new biodegradable edible film made from kefiran, an exopolysaccharide obtained from kefir grains

This study examined the feasibility of using kefiran, an exopolysaccharide obtained from kefir grains, as a new film-forming material. Kefiran-based films, with and without glycerol as plasticizer, were prepared by a casting and solvent-evaporation method. To study the impact of the incorporation of glycerol into the film matrix, physical, mechanical, and thermal properties of the films were investigated. As expected, the increase of glycerol concentration from 15% to 35% w/w increased extensibility but decreased tensile strength, implying higher mobility of polymer chains by the plasticizing effect of glycerol. Water vapour permeability of films was found to increase as the plasticizer content increased. Glass transition temperatures decreased as a result of plasticization as glycerol content increased. The properties of the films were related to their microstructure, which was observed by scanning electron microscopy. Thus, it was observed that plasticizer is a significant factor in the properties of these films and their food technology applications.

Preparation of flexible and transparent SMA films by simple composite with MBS potential for negative birefringence compensator

The brittleness of poly(styrene maleic anhydride) (SMA) was improved by compositing with elastic poly(methyl methacrylate-butadiene-styrene) (MBS) to develop it into optical film. Transparent and flexible SMA films were prepared, and the flexibility of them was checked by folding endurance test and folding bend. The transparence of SMAMBS films were proved by the transmittance and haze measurements. In actual view, the letters could be clearly observed while they were covered by prepared films. The thermal stability of them was confirmed by DSC and TGA analysis. These physical properties of films are comparable to that of polycarbonate which is widely used as optical film. Besides of these, mechanical and fracture properties of them were found to be also suitable for this purpose. Furthermore, negative birefringence could be obtained by orientationally stretching them. Such results indicate that, films prepared from composites are competent for negative birefringence optical compensator in the field of liquid crystal display. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

Preparation of Textured PZT Film on Substrates of YBaCu3O7-x/LaAIO3 by Sol-Gel Method

YBaCu3O7-x film is considered as an ideal electrode material of PZT film due to: (i) its good conductivity at room temperature; (ii) the similar perovskite structures and good lattice matching between the prepared film and YBCO substrate. Up to now, much has been reported on such preparation methods of hetero-structure PZT/YBCO as physical method PLD and magnetron sputtering, etc. The film physical properties have been studied. However, little has been done on its ferroelectric property because of the very limited thickness of PZT film prepared by these methods. In this paper, Pb1.1Zr0.52Ti0.48O3 thin film with (001)-texture and thickness of 1 um is prepared on YBCO/LaAlO3 (LAO) substrate by sol-gel method. The microstructure and the ferroelectric properties of the film are studied. The results show that both PZT and YBCO thin films have not only the same (001) orientation but good lattice matching as well. In comparison with the randomly-orientated PZT film, the remnant polarization (Pr) of the (001)-textured PZT thin film is 28.7umC/cm2 increased by over 60%. Bipolar switching cycle experiment indicates that the remnant polarization of Pt/PZT/YBCO capacitor has no observable decay after 109 cycles. This result indicates that the anti-fatigue property of the film is improved.

The influence of deposition temperature on vanadium dioxide thin films microstructure and physical properties

Vanadium dioxide thin films were successfully prepared on soda lime glass substrates using the optimised conditions for r.f-inverted cylindrical magnetron sputtering. The optimised deposition parameters were fixed and then a systematic study of the effect of deposition temperature, ranging from 450 °C to 550 °C, on the microstructure of thermochromic thin films was carried out. The deposited films were found to be well crystallised, showing strong texture corresponding to the (011) plane, indicating the presence of vanadium dioxide.

Physical properties of films made of copoly(ether-imide)s with long poly(ethylene oxide) segments

Polyimides having long poly(ethylene oxide), PEO, moieties in the main chain have been synthesized by a classical two-steps polycondensation method with good yield and high molecular weight. In contrast with previous works on this topic, essentially full conversion of the polyamic acid to polyimide was attained by heating at relatively low temperatures (around 160 °C). These copolyimides undergo an increase of phase separation between the PEO part and the polyimide one after a thermal annealing. This phase separation increases gas separation properties of membranes made up of these copolymers. An exhaustive study of polymer properties as a function of the thermal treatment has been carried out in order to figure out the origin of this behavior. The analysis performed included TGA, DSC, SAXS and mechanical testing. The polymers studied in this paper have medium thermal stability. In fact, degradation of the polyether chain under nitrogen takes place at temperatures above 300 °C. However, their thermal stabilities were much lower under oxidant atmosphere.

Nanomechanical Properties of TiO2 Granular Thin Films

Post-deposition annealing effects on nanomechanical properties of granular TiO2 films on soda-lime glass substrates were studied. In particular, the effects of Na diffusion on the films' mechanical properties were examined. TiO2 photocatalyst films, 330 nm thick, were prepared by dip-coating using a TiO2 sol, and were annealed between 100 °C and 500 °C. Film's morphology, physical and nanomechanical properties were characterized by atomic force microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, differential thermo-gravimetric analysis, and nanoindentation. Contrary to expectations, the maximum film hardness was achieved for 300°C annealing, with a value of 0.69±0.05 GPa. Higher annealing temperatures resulted in inferior mechanical properties. No pile-up or sink-in effects were observed with minimal creep for the 300 °C annealed sample. Considerable decrease in the amount of chemisorbed water was found with increasing annealing temperature, causing gel films densification, explaining the increasing trend of hardness with annealing temperature between 100 °C and 300 °C. DTA/TGA results also confirmed the weight loss and the endothermic reaction due to desorption of chemisorbed water. Decrease in hardness above 300 °C annealing is attributed to thermal diffusion of Na ions from the glass substrate, confirmed by nanoindentation tests on TiO2 films deposited on fused quartz, which did not exhibit hardness decrease after 300 °C annealing.

Physical properties of Ga-doped ZnO thin films by spray pyrolysis

Gallium doped zinc oxide (GZO) thin films were prepared using the simple, flexible and cost-effective spray pyrolysis technique. The physical properties of the films were studied as a function of increasing gallium dopant concentration from 1 to 9 at.%. The films were characterized by various methods to understand their structural, morphological, optical and electrical properties. The X-ray diffraction analysis revealed that the films were polycrystalline in nature having a hexagonal wurtzite type crystal structure with a preferred grain orientation in the (0 0 2) direction. Scanning electron microscopy (SEM) measurements reveal that the surface morphology of the films changes continuously with a decrease in the grain size due to Ga doping. All the films showed nearly 90% of transparency in the entire visible region. A blue shift of the optical band gap was observed with an increase in Ga doping. Room temperature photoluminescence (PL) measurement of the deposited films indicates incorporation of Ga in ZnO lattice. At 3 at.% Ga doping, the film has lowest resistivity of 6.8 × 10 −3 cm while the carrier concentration is highest.

The role of hydrogen-bonding interaction in poly(vinyl alcohol)/poly(acrylic acid) blending solutions and their films

The aim of this work is to investigate the hydrogen-bonding interaction in poly(vinyl alcohol) (PVA)/poly(acrylic acid) (PAA) blending system and its influence on rheological properties in solution and the physical properties in solid state. Introducing PAA into PVA solutions resulted in a thickening behavior of blend solutions. The viscosity of the solutions increased with PAA content increasing, and a maximum viscosity could be obtained when the ratio of PVA/PAA was 70/30. The intermolecular hydrogen-bonding and miscibility between PVA and PAA in solid state were investigated by differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR) and mechanical measurements. The results displayed the great influence of introducing PAA on the properties of blending films. The tensile strength increased from 89.31 MPa to 119.8 MPa and Young’s modulus improved by over 300% with increasing PAA concentration compared with those of pure PVA films. By systematically studying the rheological behaviors of solutions and the physical properties of films, the influence of hydrogen-bonding in solutions and solid states were discussed.

The chemical and physical characteristics of single-walled carbon nanotube film impact onosteoblastic cell response

Carbon-nanotube-based substrates have been shown to support the growth of different celltypes and, as such, have raised considerable interest in view of their possible use inbiomedical applications. Nanotube matrices are embedded in polymers which causeinherent changes in nanotube chemical and physical film properties. Thus, it is criticalto understand how the physical properties of the film affect the biology of thehost tissue. Here, we investigated how the physical and chemical properties ofsingle-walled carbon nanotubes (SWNT) films impact the response of MC3T3-E1 boneosteoblasts. We found that two fundamental steps in cell growth—initial attachmentto the substrate and proliferation—are strongly dependent on, respectively, theenergy and roughness of the surface. Thus, fine-tuning the properties of the filmmay represent a valid strategy to optimize the response of the biological host.

Effects of the free and pre-encapsulated calcium ions on the physical properties of whey protein edible film

Summary Effects of the free and the pre-encapsulated calcium ions on the physical properties of the whey protein isolate film were studied for improving calcium content in the edible films. At pH 8, the film-forming process was hindered by serious protein aggregation and gelation caused by 0.5% (w/w) free calcium ions added in an 8% whey protein isolate solution. If the calcium ions were pre-encapsulated in the protein microparticles (contained 17% Ca2+) using spray drying method, and then added in the film-forming solution prepared using the same protein, the calcium content could be doubled (1%, w/w) without significant effects on the physical properties of the film. The calcium release ability (55% at pH 1.2, 32% at pH 7.4 and more than 75% with the enzymes) of the film was also investigated.

Study of the physical properties of whey protein: sericin protein-blended edible films

Effects of the sericin protein on the physical properties of the whey protein isolate film including the mechanical strength, water vapor permeability, light transmission, moisture content, solubility and swelling were investigated in the present work. The mechanical strength of the whey protein film could be reinforced with 0.1% sericin caused by the hydrogen bonding between the sericin and whey protein molecules. Excess addition of the sericin promoted sericin self-aggregation which made the network microstructure of the film heterogeneous and therefore reduced its mechanical strength. The water vapor permeability of the film decreased with the sericin content; in contrast, the other physical properties of the film such as the moisture content, solubility, swelling, light transmission and transparency were not be significantly affected under the present experimental conditions.

FILM FORMING MECHANISM AND MECHANICAL AND THERMAL PROPERTIES OF WHEY PROTEIN ISOLATE-BASED EDIBLE FILMS AS AFFECTED BY PROTEIN CONCENTRATION, GLYCEROL RATIO AND PULLULAN CONTENT

ABSTRACT Tensile strength (TS), elongation at break (EAB) and elastic modulus (EM) of edible films prepared from 5, 7 and 9% whey protein isolate (WPI) plasticized with different levels of glycerol (Gly) (WPI : Gly = 3.6:1, 3:1 and 2:1) were investigated in order to completely characterize WPI-Gly films. On increasing protein concentration an increase in TS and EAB was observed. On the other hand, increasing Gly led to a decrease in TS and EM, while EAB increased. The addition of pullulan (Pul) into the film forming solution (FFS) increased EAB while TS, EM and thermal properties were reduced. This suggested that Pul had a similar effect as plasticizers. Films with higher Pul content showed lighter protein bands on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Fourier transform infrared spectroscopy showed that hydrogen bonding was high in WPI : Pul films as compared with the control. This is attributed to the protein-polysaccharide interactions brought about by the dominance of Pul in the FFS. PRACTICAL APPLICATIONS This work describes some physical properties of films based on blends of whey protein isolate (WPI) and pullulan (Pul), made after a previous study on some characteristics of films based on pure WPI plasticized by glycerol. The most studied proteins in the edible films technology being gluten and WPI, the use of Pul in mixture with WPI is considered as a new investigation to explore the utilization of WPI-Pul in edible film and coating materials applied to food products. Furthermore, the use of WPI-Pul films and coatings could potentially extend the shelf life and improve the stability of the coated products as shown by the resultant properties in this investigation and previous works.

Physical properties evolution of sputtered zirconium oxynitride films: effects of the growth temperature

Zirconium oxynitride (ZrNO) films were deposited by RF reactive magnetron sputtering in water vapour–nitrogen atmosphere varying the deposition temperature from RT to 600 °C. Optical analysis, x-ray diffraction, x-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) are the employed characterization techniques to investigate the influence of the substrate temperature on the films physical properties. It was found that the variation of the substrate temperature from RT to 600 °C caused a structural transition from cubic phase of Zr2ON2 to ZrN one, as confirmed by TEM observations too. In particular, Forouhi–Bloomer dispersion equations for optical parameters (n and k) and deconvolution of XPS spectra allowed further chemical properties be elucidated. They also permitted identification of two oxynitride phases, γ phase (Eg = 1.94 eV) and β phase (Eg = 1.7 eV), and an over-stoichiometric nitride one. The use of [Ec − Ev] values helped to confirm further the distinction between (γ, β)-phases and N-rich zirconium nitride compound, which is unachievable by using only Eg values.

Nano-crystalline Zr 2ON 2 thin films deposited by reactive magnetron sputtering

Zirconium oxynitride films were deposited by RF reactive magnetron sputtering in water vapor–nitrogen atmosphere varying the deposition temperature from RT to 600 °C. The influence of the substrate temperature on the films physical properties was investigated. The obtained films quality was evaluated using optical analysis, X-ray diffraction, X-photoelectron spectroscopy, and Secondary Ion mass spectroscopy. It was found that the variation of the substrate temperature from RT to 600 °C caused the transition from cubic phase of Zr 2ON 2 to ZrN one, as confirmed by TEM observations. In particular, a co-presence of Zr 3N 4–ZrN was detected when the deposition was performed at 400 °C. Moreover, Forouhi–Bloomer dispersion equations for extinction coefficient ( k) and deconvolution of XPS spectra are utilized to further elucidate chemical structure.

Antimicrobial and physical properties of sweet potato starch films incorporated with potassium sorbate or chitosan

Antimicrobial biodegradable films have been prepared with sweet potato starch by incorporating potassium sorbate or chitosan. Films incorporated with potassium sorbate ≥ 15% or chitosan ≥ 5% were found to have an anti- Escherichia coli effect. Staphylococcus aureus could be effectively suppressed by incorporation of chitosan at ≥10%. Whereas potassium sorbate lowers the tensile strength and elongation at break, and raises the oxygen permeability, water vapor permeability and water solubility, chitosan has the opposite effect. Fourier Transform Infrared (FT-IR) spectra analysis revealed that starch crystallinity was retarded by potassium sorbate incorporation and that hydrogen bonds were formed between chitosan and starch. This explained the modification of the mechanical and physical properties of the films by the incorporation of these two antimicrobial agents.

Transition Metal Binary Oxides for ReRAM Applications

Resistive switching characteristics of polycrystalline nickel oxide were studied for non volatile memory applications. NiO was deposited by atomic layer deposition and electron beam evaporation on silicon and various metal bottom electrodes. After an initial electroforming step, NiO based devices with Pt top electrode and Si, Pt, Ni, TiN or W bottom electrodes exihibit reproducible unipolar switching. The film physical properties as well as electrode combinations influence the programming voltages and resistance window. While Pt and Si electrodes give a reduced dispersion of programming voltages and currents, the largest resistance window (up to four order of magnitude) is obtained when W is used. Preliminary data on the switching properties of amorphous Nb2O5 and polycrystalline ZrO2 films are also discussed.