conventional cleaning process. These results corroborate with adherence results, show- ing how these films are well adhered to the substrate, and can support an abrasion pro- cedure, like the one produced by cleaning. It is well known that wear is closely related to the adhesion of thin film to the substrates. If the film adherence is poor, the film will wear off quickly. If the film adherence is good, the film will resist to wear. Therefore, TiO 2 and TiO 2 /SiO2films have exhibited good mechanical properties which are re-
gas dry was done on the Corning 7059 substrates. Processing conditions for obtaining ultrathin m c-Si films on oxide and epi-Si films on crystalline Si substrates are summarized in Table I. Note that two different sets of epi-Si deposition conditions were used. To study the initial stages of m c-Si film growth, a series of films ranging from approximately 5 to 80 Å was deposited on SiO2 . Using in vacuo AES, the decay of the oxygen KLL substrate signal due to overlayer growth was analyzed for various film thicknesses to ascertain the growth mechanism of the film. To assess the crystallinity of the seed layer, ex situ RHEED and SE were employed. Prior to RHEED imaging, the native oxide was stripped us- ing a dilute HF solution. Grazing angle ~; 3° ! diffraction images were obtained at 10 keV accelerating voltage. For SE measurements, the shift in optical phase and the polarization upon reflection at 75° from the surface normal were analyzed utilizing a detector operating in the 1.6–3.0 eV spectral range.
The thin film thicknesses were determined by rotating compensator spectroscopic ellipsometry (SE; M-2000FI from J. A. Woolam Co). The ellipsometric angles Psi and Delta were recorded in the range from 210 nm to 1680 nm at a fixed angle position of 75 ◦ . Thickness was obtained by fitting a layer stack model based on reference data for the refractive indices to the measured data. The resulting simulated stack for the as-deposited sample consists of three parts, a fused silica substrate, a bulk layer which was described by a Bruggeman-effective medium approximation (EMA) with different amounts of silicon dioxide and amorphous silicon, and a silicon dioxide top layer. For the annealed samples, Bruggeman EMAs were expanded by adding contributions of crystalline silicon. To validate the obtained thicknesses, selected samples were cross-checked with profilometry using a Veeco DEKTAK 8000 equipped with a 12.5 µm stylus, and punctually by cross-sectional TEM.
At a dc power of 35 W and an Ar gas flow of 20 sccm, samples Nos. 1-4 (see Table 1) were deposited at gas pressures (P) of 5, 4, 3, and 2 mTorr, respectively. Figure 2 is a general AFM image of Ir films deposited in this study. The rms roughness values calculated from AFM were only 0.84, 0.44, 0.41, 0.3 nm, respectively, suggesting that the films consisted of closely packed grains with very fine grain sizes. The average roughness decreased slightly with decreasing gas pressure. This was somewhat expected, because lower gas pressure reduced incident working gas (Ar) entrapment in the film, and increased sputtering particle energies (due to fewer collisions with the sputter inert gas) when they strike the substrate, resulting in better adhesion .
Silicon oxide ( ) Thinfilms are the most extensively studied among different deposited materials. Because of their technological importance as dielectric protective layers in semiconductor layers, integrated circuits, waveguides, and many other applications. However, high-quality films are required for these applications. has many interesting properties that make it suitable for thin film applications . SiO2thinfilms have wide applications in the biomaterial
flowchart of the steps involved in preparing the solution and thin film deposition by dip coating process. Prior to deposition, substrates were subjected to thorough cleaning process with double distilled water followed by ultrasonic cleaning in acetone and dried in hot air. The cleaned substrates were dip coated with dip speeds and retrieval speeds ranging from 1mm/sec to 4mm/sec followed by heating at 70 o C between successive dips. The thinfilms are annealed at 200 ºC, 400 ºC and 600 ºC temperatures for 3 hours in the air ambient. All deposited films have visual stability which has confirmed through scotch tape test. Characterization
tive oxide of GaN can improve the quality of the interface and dielectric layer of the GaN MOS system. For the oxide film deposition by a plasma-assisted process, ex situ wet chemical and in situ removal of the air-grown native oxide does not guarantee that there is no interfacial oxide because the presence of oxidant and excitation very often leads to the growth of an oxide on the substrate surface. When SiO2thinfilms were deposited on Si, Ge, GaAs, and CdTe using remote plasma-enhanced chemical vapor deposition ( RPECVD ) , the substrates were slightly consumed by plasma-activated species that diffused though the deposited oxide layer and oxidized the underlying substrate. 6–8 These parasitic reactions, or subcutaneous oxidation, during oxide film deposition by the RPECVD process degrade the electri- cal characteristics of the interface. To prevent the subcutane- ous oxidation of the GaAs and Ge, a thin sacrificial Si layer was deposited before the deposition of the SiO2thin film. 6–8 To prepare a device-quality Si-SiO2 interface and dielectric bulk film 共 SiO2 兲 , the superficially thin oxide layer 共⬃ 0.6 nm 兲 is formed on the silicon substrate by a remote plasma-assisted oxidation (RPAO) process, and the remain- der of the oxide layer is deposited by a RPECVD process. 9 After formation of ⬃ 0.6 nm of oxide in ⬃ 15 s, the oxidation rate slows down to ⬃ 0.3– 0.4 nm/ min. Therefore, during plasma-enhanced deposition at rates of ⬃ 2.5– 5 nm/ min, plasma-activated O species are consumed faster by deposi- tion reactions with SiH 4 than by continued oxidation at the buried Si-SiO2 interface.
Surgical procedures were carried out under general anes- thesia in aseptic conditions. To anesthetize the animals, a mixture of 1 mL ketamine hydrochloride (100 mg/mL) and 0.5 mL xylazine hydrochloride (20 mg/mL) added to 10 mL of 0.9% NaCl was prepared and injected intraperitoneally at a dose of 1 mL/100 mg body weight. The animal leg was shaved, washed in chlorhexidine solution, and positioned and clothed in sterile sheets on the operating table. A curved incision measuring 10–15 mm was made on the anterolateral knee surface; the joint capsule was dissected, incised, and then the patella subluxated, exposing the femur intercondylar fossa (Figure 1A). Femur’s medullary canal was opened through the fossa using a 1.2 mm drill and the specimen was positioned in the medullary canal (Figure 1B). Subsequently, the wound was closed and each layer separately sutured: the joint capsule, fascia, subcutaneous tissues, and skin. X-rays were taken just after surgery to confirm proper location of the implants (distal metaphyseal–diaphyseal; Figure 1C). The animals were sacrificed after 12 weeks by administering intraperitoneal injections of pentobarbital (Morbital) at a dose of 2 mL/kg body weight. Distal femurs were dissected and evaluation carried out.
wide . It is true that the mobility of network-modifying cation controls the composition and structure of nucleating phases which implies that viscosity controlled by network formers is not an important parameter for nucleation. Wittman et al studied on surface nucleation and growth of Anorthite (CaO.Al 2 O 3 .2SiO 2 ) glass . The results showed that surface nucleation occurs and the crystal grew
densities beyond 11.6 Gbits/in². 4 The hard drive read heads in the current generation of computer hard drives utilize structures that consist of two layers of metallic ferromagnets (such as., Fe-Ni alloy) separated by a thin spacer layer (in the order of nm) of normal metal (such as Cr or Cu) 5 . The flow of current across the spacer layer is facilitated or inhibited depending on whether the magnetic moments of the two ferromagnets layers are parallel or anti-parallel to each other. Devices have been demonstrated with GMR ratios (i.e. the magnitude of the change, (Antiparallel Resistance - Parallel Resistance) / Parallel Resistance) as high as 60-70%.
thoroughly mixing its fine powder with 30 wt % organic binder (ethyl cellulose), 30 wt % solvent (2- butoxyethanol and terpineol) and 15 ml dispersant. The films were prepared on glass substrate by using screen printing followed by drying under tungsten filament lamp. Dried films were fired at 450 °C for 1 h for the complete removal of organic binder. The gas sensing property of three sensors have been studied using static gas sensing system towards various gases. The current developed was measured by a digital Picoammeter by applying constant voltage to the
application, several criteria have to be considered such as coating morphology, deposition rate and coverage, inter- facial quality, and industrial applicability. Among these methods, the ALD process is based on the sequential use of self-terminating surface reactions, which is perfect for the deposition of metal oxide layers with atomic layer con- trol on geometrical nanostructures with high aspect ratios. Compared with other more common techniques, ALD pos- sesses several advantages in the deposition of TiO 2 , such as precise thickness control, extremely conformal coating for nanostructures, excellent large-area uniformity, strong bond- ing strength, low growth temperature, good reproducibility and straightforward scale-up, and applicability to sensitive substrates (ie, biomaterials). 25
As shown in Figure 2, both Se@SiO2 and MPS induced SOD and GSH-PX, compared with the control group. The levels of SOD and GSH-PX in the MPS plus Se@SiO2 group were similar to those in the MPS group (Figure 2A and B). The wet-to-dry weight ratio was significantly decreased in the MPS group compared with the Se@SiO2 group, whereas the wet-to-dry weight ratio in the MPS plus Se@ SiO2 group was comparable to that in the MPS group (Figure 2C). Western blot was also used to determine the inflammation factors including interleukin (IL)-1 β and tumor necrosis factor-alpha (TNF- α ) in the control group, Se@ SiO2 group, MPS group, and MPS + Se@SiO2 group. The results showed that compared with the control group, Se@ SiO2 did not significantly decrease the levels of IL-1 β and TNF- α (Figure 2D–F). However, MPS dramatically reduced the IL-1 β level and TNF- α level (Figure 2D–F). The addition
various methods such as sol–gel method , cathodic electrodeposition , plasma enhanced chemical vapor deposition (PECVD) , vacuum arc plasma evaporation  and sputtering [19-21]. In comparison with other methods, sputter depositions is one of the most widely techniques for large-area uniform coatings with high packing density and strong adhesion . In addition, this method is easily to apply in industry and to accomplish thin film which has good quality in the large area [23-24]. The reactive sputtering technique for coating nanocrystalline TiO 2thin film are mainly use as radio frequency (RF) and
From that figure we see that the addition of PEG in various molecular weights decreases contact angle (without any fogging), but one and others are not so different in the qualitative test. Those three samples give almost same performances. It indicated that PEG with molecular weight 1000-6000 is effective enough to modify TiO 2 film so that
The XRD pattern indicates that the films are polycrystalline suggesting a complete perovskite phase formation with the absence of secondary phase. The absence of the secondary phase (derivatives of tin oxide) increases the dielectric constant and reduces the leakage current density . The XRD pattern shows that the increased dopant concentration (1 - 4%) leads to increase in intensity of diffraction peaks. XRD pattern reveals the improvement in crystalline natureas the Tin is replaced with Ti. The lattice constant (a) of the samples are calculated from 2θ values of the XRD pattern using Check Cell software and manually through Bragg’s law (Table 1). The (110) peak shifts towards left in the XRD pattern, which is due to the variation in the lattice constant. The peak positions and full width half maximum values of all the films are listed in Table 2. Using these values, the grain size was calculated using Scherrer formula and listed in Table 1.
Raman spectrum of the DMPS thin film. This arose from amorphous Si, and de- creased in intensity upon P doping. Thus, P was doped in polysilanes, and PMPS acted as an n-type semiconductor. Solar cells with PMPS(P)/P3HT, DMPS(P)/ P3HT and DPPS(P)/P3HT heterojunction structures were fabricated and exhi- bited photovoltaic behavior.
Figure 3A shows TEM images of CS-SA/DOX and CS-SA/SiO2 /DOX nanoparticles. In contrast with CS-SA/ DOX, dark rings around the nanoparticles could be observed on all CS-SA/SiO2 /DOX nanoparticles images. This likely resulted from the SiO2 -deposition effect. During preparation, TEOS was introduced as a precursor for the Sol-Gel reaction, and the hydrolysis reaction was first carried out in acidic environment; the condensation reaction followed after the pH was adjusted to neutral. When the mixed solution was added (TEOS and DOX) into the CS-SA solution, DOX could enter into micelle cores using hydrophobic interaction, while TEOS dispersed in the water environment and took part in the Sol-Gel reaction. The reaction product, silanols, could
Results: The nanotopographic features of material surface, stoichiometry, and wetting proper- ties were found to be significant factors in dictating platelet behavior and cell viability. The TiBN films with higher nitrogen contents were less thrombogenic compared with the biased carbon films and control. The carbon hybridization in carbon films and hydrophilicity, which were strongly dependent on the deposition process and its parameters, affected the thrombo- genicity potential. The hydrophobic CNT materials with high nanoroughness exhibited less hemocompatibility in comparison with the other classes of materials. All the thin film groups exhibited good cytocompatibility, with the surface roughness and surface free energy influenc- ing the viability of cells.