micro-Raman Analyses Research Articles

Complementary microstructural and chemical analyses of Sepia officinalis endoskeleton

Cuttlebone exhibiting high compressive strength is a very interesting material from the biomimetic materials' technology point of view. Its microstructure and chemical composition were characterized by complementary analytical techniques. Structural features of the skeleton were revealed by SEM, micro-Raman, FT-IR and XRD measurements. XRD analyses showed that the only mineral phase present in the samples is aragonite. 2D-maps obtained from micro-Raman analyses for peaks attributed to aragonite (1100 cm − 1 ) and chitin (1660 cm − 1 ) revealed that the septa are richer in chitin and pillars in aragonite. 2D-distributions of elements detected by a electron microprobe showed that Ca-rich locations are poor in Mg, Na, and Br. Ca is mainly present at those locations where aragonite prevails. Bromine, sodium and magnesium are most likely located in the organic matrix. The average content of the elements, as determined by ICP-OES, was: Na — 1.0%, Mg — 0.133%, K — 0.26%, Fe — 0.03% and Sr — 0.28%. Using the elemental CHN analysis the following amounts of nitrogen, carbon and hydrogen were detected: 1.42%, 15.36% and 0.68%, respectively. The elemental analysis together with TGA measurements allowed evaluating the approximate concentration of organic matter in the cuttlebone at the level of 10%.

Characterisation of mackinawite by Raman spectroscopy: Effects of crystallisation, drying and oxidation

Iron(II) sulphides were precipitated by mixing FeCl 2 · 4H 2O (or FeSO 4 · 7H 2O) and Na 2S aqueous solutions with various [Fe(II)]/[S(-II)] concentration ratios at [Fe(II)] = 0.1 mol L −1. They were analysed by micro-Raman spectroscopy and X-ray diffraction immediately after precipitation and after various times of ageing in suspension at room temperature. In any case, the initial precipitate was nanocrystalline mackinawite. Its Raman spectrum is made of two sharp peaks at 208 ± 1 and 282 ± 1 cm −1. For [Fe(II)]/[S(-II)] ⩾ 1, ageing of the precipitate led to crystalline mackinawite, as testified by X-ray diffraction. The Raman spectrum of crystalline Fe(II) mackinawite shows three main peaks at 208, 256 and 298 cm −1. Drying of nanocrystalline mackinawite under an argon flow favoured crystallisation. The removal of interparticle and surface adsorbed water molecules led to coalescence of the nanoparticles and increase of the size of the domains of coherent scattering. For [Fe(II)]/[S(-II)] = 1/2, the precipitate still consisted of nanocrystalline mackinawite after 70 days of ageing. Finally, the early oxidation stages of mackinawite led to the formation of Fe(III) cations inside the tetrahedral sites of the crystal structure. The most oxidised form of Fe(III)-containing mackinawite is characterised by a Raman spectrum with sharp peaks at 125, 175, 256, 312 and 322 cm −1, and a large vibration band at 350–355 cm −1 that may be attributed to stretching modes of Fe(III)-S tetrahedrons. Analyses of the rust layers of a roman ingot that remained 20 centuries in the Mediterranean Sea revealed the presence of iron sulphides, more likely generated by sulphate-reducing bacteria. Micro-Raman analyses demonstrated the presence of nanocrystalline mackinawite and Fe(III)-containing mackinawite.

Batch and continuous precipitation of scorodite from dilute industrial solutions

Enriched arsenic precipitates were obtained from dilute industrial As(III) solutions (1.1–0.1 g As/L) at 95 °C in batch and continuous reactor operations. A complete and fast oxidation of As(III) was obtained at room temperature with 20% excess of hydrogen peroxide. Arsenic removal varied from 80.5 to 94.6% and increased with the total surface area (SSA) of the seed. SSA higher than 270 m 2/g was required to promote an arsenic removal of approximately 85%. Recycling of solids was necessary to achieve high yields of arsenic removal in continuous operation. Approximately 75 to 85% As was removed in 1 h of residence time in the MSMPRR (Mixed Suspension Mixed Product Removal with Solids Recycle) reactor; the rate of crystal growth was calculated as 10 − 12 m/s. Arsenic removal was not favored by the excess of iron in the solution. TCLP (Toxicity Characterization Leaching Procedure) testing indicated that ageing plays an important role in the leachability of scorodite, which decreased from 13.6 mg As/L to 0.1 mg As/L after 8 h in a batch reactor. The decrease in As leachability was related to the decrease in the SSA (14 m 2/g to 0.9 m 2/g after 62 h in the MSMPRR) as a combination of crystal growth (1.6 μm to 5.3 μm) and densification. Scorodite was the only arsenic phase identified by X-ray diffraction and micro-Raman analyses of the precipitates.

San Francesco d'Assisi (Apulia, South Italy): Study of a manipulated 13th century panel painting by complementary diagnostic techniques

The panel painting “S. Francesco d'Assisi” (Museo diocesano “Mons. A. Marena”, Bitonto, Italy), executed around the half of the 13th century and manipulated at least two times in the following centuries, was studied by various complementary analytical techniques in order to characterise the original medieval painting technique and the subsequent editions. Optical microscopy (OM), scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS), micro-Raman spectroscopy and pyrolysis–gas chromatography–mass spectrometry (Py-GC/MS) were applied on various samples taken from significant parts of the painting. Several in situ micro-Raman analyses were also performed. The results obtained confirm that the painting belongs to the 13th century Italian painting tradition. Furthermore, combination of various analytical techniques revealed that the 13th century original background, which now appears dark grey, was realised by applying a tin foil covered by a mecca layer composed of siccative oil and heated Pinaceae resin. Thus, originally the background should have had a gold-like appearance. The most important manipulation of the painting of S. Francesco probably dates back to the 16th century but shows a quite traditional technique.

Polymorphism and Phase Control in Titanyl Phthalocyanine Thin Films Grown by Supersonic Molecular Beam Deposition

Polymorphism in the growth of titanyl phthalocyanine films on dielectric substrates has been systematically studied by UV absorption and micro-Raman analyses, correlating structure and optical properties. We explored different growth regimes as a function of substrate temperature and growth rate using hyperthermal seeded supersonic beams. We identify and discuss specific signatures in micro-Raman spectra specifically correlated to the different phases and demonstrate the unprecedented ability of growing crystalline films and controlling the relative abundance of the different phases (amorphous, phase I, and phase II) by the beam parameters. We envisage the very promising perspective of controlling polymorphism at low temperatures via supersonic beam growth, paving the way for better performing devices.

Ultra-High Oxidation Resistance of Suspended Single-Wall Carbon Nanotube Bundles Grown by an "All-Laser" Process

Single-wall carbon nanotubes (SWCNTs) were laterally grown on SiO2/Si substrates by means of an "all-laser" growth process. Our "all-laser" process stands out by its exclusive use of the same pulsed UV laser, first, to deposit the CoNi nanocatalyst and, second, to grow SWCNTs through the laser ablation of a pure graphite target. The "all-laser" grown SWCNTs generally self-assemble into bundles (5-15 nm-diam.) sprouting from the CoNi nanocatalyst and laterally bridging the 2 microm gap separating adjacent catalysed electrodes (in either "suspended" or "on-substrate" geometries). A comparative study of the oxidation resistance of both suspended and on-substrate SWCNTs was achieved. The "all-laser" grown SWCNTs were subjected to annealing under flowing oxygen at temperatures ranging from 200 to 1100 degrees C. Systematic scanning electron microscopy observations combined with micro-Raman analyses revealed that more than 20% of suspended nanotubes were still stable at temperatures as high as 900 degrees C under flowing O2 while the on-substrate counterpart were completely burnt out at this temperature. Accordingly, the activation energy, as deduced from the Arrhenius plot, of the suspended SWCNTs is found to be as high as approximately 180 kJ mol(-1) (approximately 9 times higher than that of the on-substrate ones). The high quality (almost defect-free) of the nanotubes synthesized by the "all-laser" approach, their protected tips into the embedded CoNi catalyst nanolayer together with their suspended geometry are thought to be responsible for their unprecedented ultra-high oxidation resistance. This opens up new prospects for the use of these suspended nanotubes into nanodevices that have to operate under highly oxidizing environments.

Study of the structural changes induced by air oxidation in Ti–Si–N hard coatings

3-μm thick Ti–Si–N coatings were deposited on polished X38CrMoV5 substrates by sputtering a composite Ti–Si target in Ar–N 2 reactive mixture. Oxidation tests were performed in air at 700 °C during 2 h. Whatever the silicon content in the range 0–4 at.%, no silicon containing compound was detected by XRD before air oxidation and only the TiN phase was evidenced. The mean grain size estimated from the full width at half maximum of the TiN (111) diffraction peak was close to 10 nm. As commonly reported for Ti–Si–N films, the hardness showed a maximum at 51 GPa versus the Si content. After oxidation of the TiN film, XRD and micro-Raman analyses revealed the occurrence of the TiO 2 rutile phase in the whole films thickness, indicating the total oxidation of the TiN film. On the other hand, the addition of silicon into the TiN-based coatings induced a strong improvement of the film oxidation resistance. Indeed, the oxide thickness was reduced to nearly 0.4 μm for films containing 1.2 at.% Si. Moreover, the silicon addition gave rise to a change in the structure of the oxide layer. In fact, weak diffraction peaks of the TiO 2 anatase phase were detected by XRD. The presence of the anatase phase was clearly shown by micro-Raman spectroscopy, which is a very sensitive method to detect this TiO 2 phase. The intensity of the anatase micro-Raman bands increased with the silicon concentration, whereas that of rutile decreased.

Studies on capacity fading mechanism of graphite anode for Li-ion battery

It is of great importance to improve the electrochemical performance of graphitic anode materials since they are dominantly used in practical lithium ion battery and still will be the main component as anode material in the future. By SEM, XPS, Micro-Raman and EDX analyses of graphite electrodes before and after discharge/charge cycle, it is found that capacity fading is strongly related to the dispersion of conductive. Homogeneous dispersion of conductive resulted in good cycle performance. However, for the poorly fabricated electrode, with heterogeneous dispersion of conductive, it gives rise to the formation of imperfect SEI film in the first cycle and subsequent continual decomposition of the electrolyte, leading to large amounts of nonconductive surface deposits consisting of Li 2CO 3 and LiF. As a result, its irreversible capacity is high and capacity retention is poor. Thus, homogeneous dispersion of conductive is necessary to obtain good performance for graphitic anode electrode. The formation of Li 2CO 3 and LiF during repeated cycling is attributed to the inhomogeneous distribution of the overpotential throughout the fabricated electrode.

Influence of nickel content on the chemical bonding character of LiMn 2− xNi xO 4 spinel oxides

A relationship between the chemical bonding nature of LiMn 2− x Ni x O 4 and the Ni content has been systematically investigated. According to X-ray diffraction analysis, nickel-substituted lithium manganates crystallize with a cubic spinel structure without the formation of any impurity phase such as NiO in the present substitution range of 0 ≤ x ≤ 0.4. Micro-Raman analysis showed that Ni substitution gave rise to an increase in the intensities and energies of the two main phonon lines at ∼580 and ∼620 cm −1, indicating enhancement of the average Mn oxidation states and reinforcement of the Mn O bonds. This was confirmed by Mn K-edge X-ray absorption spectroscopic (XAS) analysis. Also, a new phonon line appeared at ∼495 cm −1 after the Ni substitution, which can be assigned as an Ni–O vibration mode rather than as a T 2g(2) mode of LiMn 2O 4. Ni K-edge XAS and micro-Raman analyses clearly demonstrate that divalent nickel ions existed in the octahedral sites of the cubic spinel lattice without a significant change in the chemical environment with the Ni content. In this regard, the poor electrochemical performance of heavily Ni-substituted compounds for the 3 V region is not attributable to the variation in the local environment of Ni ions with the Ni content, but to the low structural stability of the substituted NiO 6 octahedra.

Nanoindentation-Induced Phase Transformations in Ge Studied by Electron Microscopy and Raman Spectroscopy

The sequences of hydrostatic pressure-induced phase transformations in Si and Ge have been established in diamond anvil studies. At sufficient pressure the normal diamond-cubic structure Si-I/Ge-I transforms to the metallic {beta}-tin structure; upon unloading, several metastable phases can form depending on the maximum load and/or unloading rate. In the case of Ge, the metastable phases are Ge-III(ST12) or Ge-IV(BC8). Since microstructural investigations of Si indents have revealed metastable crystalline phases, it was expected that Ge indents could demonstrate similar phenomena. However, there is no prior evidence of phase transformations from indentation load-displacement (P-h) curves or electron microscopy. In this study, nanoindentations were made on undoped (100) Ge at room temperature with triangular pyramidal indenters with centerline-to-face angles of 35{sup o} (cube-corner) and 65{sup o} (Berkovich) at loads of 10, 50 and 80 mN and a loading/unloading rate of 5mN/s. The indents were examined by SEM, micro-Raman analyses and TEM of cross-sections prepared by dual-beam FIB milling.

Carbon nanotube synthesis and parametric study using CaCO 3 nanocrystals as catalyst support by CVD

The preparation of multi-walled carbon nanotubes (MWCNTs) by chemical vapor deposition (CVD) method using nanocrystalline CaCO 3 as metal catalyst support was investigated, where acetylene was used as carbon source, and Co, Fe and Ni, as well as their bimetallic compounds as the active component of the catalyst. The smaller size of the CaCO 3 support led to a much higher yield of CNTs than previously reported. It was noteworthy that the best performance was Fe-Co nanoparticles, which gave a high yield of CNTs, as judged by experimental results. Growth temperature affected catalytic activity and the disintegration of the support. The raw product was purified to a high level, with little damage on the CNT structure, as confirmed by thermal gravimetric (TG), micro-Raman and transmission electron microscopy (TEM) analyses.

Spectroscopic identification of protective and non-protective corrosion coatings on steel structures in marine environments

Corrosion research, and the need to fully understand the effects that environmental conditions have on the performance of structural steels, is one area in which Mössbauer spectroscopy has become a required analytical technique. This is in part due to the need to identify and quantify the nanophase iron oxides that form on and protect certain structural steels, and that are nearly transparent to most other spectroscopic techniques. In conjunction with X-ray diffraction and micro-Raman analyses, the iron oxides that form the rusts on steels corroded in different marine and other environments can be completely identified and mapped within the rust coating. The spectroscopic analyses can be used to determine the nature of the environment in which structural steels have been, and these act as a monitor of the corrosion itself. Mössbauer spectroscopy is playing an important role in a new corrosion program in the United States and Japan in which steel bridges, old and new, are being evaluated for corrosion problems that may reduce their serviceable lifetimes. Mössbauer spectroscopy has been used to characterize the corrosion products that form the protective patina on weathering steel, as well those that form in adverse environments in which the oxide coating is not adherent or protective to the steel. Mössbauer spectroscopy has also become an important analytical technique for investigating the corrosion products that have formed on archeological artifacts, and it is providing guidance to aid in the removal of the oxides necessary for their conservation.

Characterisation of dispersed organic matter from lower Palaeozoic metasedimentary rocks by organic petrography, X-ray diffraction and micro-Raman spectroscopy analyses

Dispersed organic matter (DOM) concentrates of C-rich rocks from areas with different metamorphic characteristics were studied by organic petrography, X-ray diffraction (XRD) and micro-Raman spectroscopy analysis. The concentrates contain several types of DOM with different morphologies, reflectance, X-ray diffraction and micro-Raman characteristics. Four different morphological types were identified in the two studied areas. The different types have different distributions and their reflectance is quite variable in the four types, with a dominance of the highest reflectance values in the DOM from the area with the highest metamorphic grade. XRD analyses of samples from the areas reveal the presence of fine graphite together with non-graphitised carbons. The Raman spectral profiles show the usual bands G (1582 cm −1) and D1 (1350 cm −1), on the first-order Raman spectrum, and S1 (2700 cm −1) on the second-order spectrum. Additional weaker bands, D2 (1620 cm −1), and more rarely D3 (1500 cm −1) and S2 (2900 cm −1), are present. These are characteristic for disordered carbons in the different types of DOM and in both studied areas. However, the Raman parameters (D1/G intensity area ratio and the frequency and width of G band) indicate variable degrees of organisation in all DOM types. The existence of different types of DOM with different degrees of ordering in the same lithologies and metamorphic grade seems to be related to different organic precursors, as they are graphitised to different extents under the same metamorphic conditions. However, in the same lithologies and metamorphic grade, the existence of various stages of graphitisation within the same type of DOM can only be explained though the interaction of DOM with the metamorphic fluids present in the rocks. The ordering graphitisation process may be due to the existence of metamorphic fluid circulation events with a variety of compositions.

Study on the technique of the Roman age mural paintings by micro-XRF with Polycapillary Conic Collimator and micro-Raman analyses

XRF and micro-Raman stratigraphic microanalyses of fragments of some mural paintings, belonging to the Archaeological Site of Oplonti (Napoli) and the Vigna Barberini site in the Palatino (Roma), were performed. In order to collimate the fluorescence X-rays emitted by the samples, an X-ray polycapillary conic collimator (PCC) has been used in front of the detector. This device arrangement is compact, versatile, and portable. The nature of the pigments, the compositional elements, and the thickness of the fragment layers have been studied. The stratigraphic analysis partially confirms the preparation techniques described by Plinius and Vitruvius; moreover it confirms the hypothesis that the artifacts are not fresco paintings. This work has been conducted within the context of a wider research on the Roman age mural paintings.

Micro-Raman spectroscopy for stress analysis on large area diamond/Ti6Al4V electrodes

Residual stress in boron doped diamond films grown on perforated and non-perforated titanium alloy substrates (Ti6Al4V) have been investigated. Diamond films were deposited at 870 K and 6.5×10 3 Pa by the conventional hot filament chemical vapor deposition technique (HFCVD) using a gas mixture of methane 1.0 vol.% in hydrogen. For controlling the B/C ratio it was necessary an additional H 2 line that passed through a bubbler containing B 2O 3 dissolved in methanol. Large substrates with a geometric area of 12 cm 2 were fixed in a rotation mechanism that improves the film uniformity. Perforated substrates were obtained from laser machining and promoted an increase of approximately 30% on surface geometric area when compared with similar non-perforated sample. Scanning electron microcopy (SEM) has evidenced a faceted polycrystalline grains with orientation (111) and (100) of approximately 1 μm in size for a film thickness of 1.5 μm. From micro-Raman analyses, the stresses were evaluated in many points on samples surface by using the summation method. The contribution of the pure diamond and the non-diamond phases was also analyzed. These results were imperative for comparing the total residual stress in perforated and non-perforated samples and show a good agreement for both of them. Higher compressive stress values are associated with perforated sample that presented lower amount of sp 3 bond. The relative higher concentration of non-diamond phase among the crystalline grains can help the structure relaxing promoting a decrease of intrinsic stress. Total stress result in both samples was compressive but in the samples edges the values are higher due to the thermal component to be a dominant contribution in this region.

Variation of chemical bonding nature of layered LiMnO 2 upon delithiation/relithiation and Cr substitution

X-ray absorption spectroscopic (XAS) and micro-Raman analyses have been performed to investigate the effect of delithiation/relithiation reaction on the electronic and crystal structures of layered LiMnO 2. From the spectroscopic results presented here, it becomes clear that the local structure around manganese in LiMnO 2 is changed from a layered α-NaFeO 2-type structure to a spinel-like one upon Li deintercalation–intercalation reaction. Such results highlight the lattice instability of layered manganese oxide for the extraction of interlayer lithium, which is responsible for the remarkable capacity fading. On the basis of the present experimental findings, we have prepared the chromium-substituted LiMn 1− x Cr x O 2 (0≤ x≤0.15) oxides to improve the electrochemical performance of layered lithium manganate. As expected, the electrochemical measurements clarify that the Cr-substituted compounds possess better electrochemical properties than the pristine LiMnO 2. According to the XAS and micro-Raman studies for these compounds, it is found that the trivalent chromium ions are fixed to the octahedral site of MnO 2 layer before and after electrochemical charge–discharge process, and that the manganese ion can be stabilized through the shortening of (MnO) bond distances. In this regard, the improved electrochemical performance of LiMn 1− x Cr x O 2 is surely attributed to the stabilization of layered lithium manganate lattice upon replacement of Mn with Cr.

Micro-Raman investigation of strain in GaN and AlxGa1−xN/GaN heterostructures grown on Si(111)

Using micro-Raman spectroscopy, we have studied the vibrational properties of GaN and Al0.5Ga0.5N/GaN long period superlattices (SLs) grown on Si(111). Crack-free areas of GaN layers grown on Si(111) exhibit residual tensile stress, which is evidenced by the red shift of the frequency of E2(TO) phonon. We have derived the strain cartography in GaN and Al0.5Ga0.5N/GaN long period SLs, which shows that cracking leads to strain relaxation. In addition, the AlGaN layers on GaN introduce an additional component of compressive strain into the GaN layers in these SLs. The amount of strain is quantified using micro-Raman analyses and by taking into account the elastic properties of GaN and AlGaN. By introducing a thin, low temperature InGaN interlayer, we could significantly reduce the crack density of the GaN layer.

Morphology and structure of nanocrystalline p-doped silicon films produced by hot wire technique

In this paper we report results of nanocrystalline p-doped silicon films produced by hot wire chemical vapour deposition technique with Ta filaments, using a pre-mixed gas containing silane, diborane, methane, helium and hydrogen. The data obtained show that the films produced exhibit good optoelectronic properties and show a surface morphology dependent on the filament temperature and hydrogen dilution. The increase in the filament temperature, keeping constant the hydrogen dilution (87%), promotes the preferential growth of the crystals in the {2 2 0} direction, giving rise to a pyramidal-like surface structure. This behaviour is observed by the SEM micrographs as well as by the micro-Raman and X-ray diffraction analyses. On the other hand, using a constant filament temperature, the increase in the hydrogen dilution contributes to an increase in both {1 1 1} and {2 2 0} diffraction peaks. Thus, by combining both filament temperature and hydrogen dilution the film surface can be controlled from a smooth to a pyramidal-like structure, without decreasing the crystalline fraction of the films. The structure and morphology is also reflected in the stability of the electrical dark conductivity. We observe that this property depends on the temperature range of the measurements and on the exposition time of films to the atmospheric conditions.

Application of phase contrast imaging atomic force microscopy to tribofilms on DLC coatings

Tribofilms formed in the rubbing surfaces are closely related to wear mechanisms and steady-state friction in sliding contacts. However, their small thickness, inhomogeneity and discontinuity are the factors that hinder the evaluation of their micromechanical properties. The phase contrast images in tapping mode atomic force microscopy allow an estimation of inhomogeneity in micromechanical properties of the sample surfaces. The purpose of this investigation is to examine how the phase contrast images contribute to the characterization of thin tribofilms. Surfaces of diamond-like-carbon (DLC) coatings before and after friction contact against a steel ball slider were investigated in this study. The chemical characteristics of the worn surfaces were studied by micro-Raman spectroscopy, Auger electron spectroscopy (AES) and secondary ion mass spectroscopy (SIMS) and these results were discussed in association with the phase contrast images. A three-dimensional simulation of the real contact area was also conducted and the pressure distribution obtained by this simulation was compared with the phase contrast image obtained at the same area. The phase contrast images revealed a significant inhomogeneity of the worn surfaces. Thin tribofilms were formed at the real contact regions and their thickness increased at the locations experiencing higher contact pressure. The tribofilms that represented as darker grey scale values indicated that they were less stiff than the initial DLC coating. The comparison of the phase contrast images with the results of micro-Raman, AES and SIMS analyses led to a speculation that the tribolfilms, composed almost of carbon element, may be graphite films or films mainly possessing graphitic property. The phase contrast imaging in atomic force microscopy showed promise as an effective tool for better understanding micromechanical properties of worn surfaces and wear mechanisms.

Pyrolytic Carbon Deposition on Porous Cathode Tubes and Its Use as an Interlayer for Solid Oxide Fuel Cell Zirconia Electrolyte Fabrication

A high-quality fugitive pyrolytic carbon (PyC) film is used as an interlayer material in fabricating solid oxide fuel cells (SOFCs) by electrophoretic deposition (EPD). The carbon must both be highly conducting and burn away cleanly; hence, a graphitic or pyrolytic carbon is required. In this investigation, optimum conditions for PyC deposition from propylene pyrolysis (i.e., CVD) were ascertained. Propylene was decomposed at temperatures of 725, 775, and 825°C and at 1 atm pressure with different residence times (10-20 s) onto a porous tube surface. Depending on the temperature and residence time, two different ranges of carbon deposit reactivities were obtained, corresponding to disordered and ordered carbon states, respectively. Temperature-programmed oxidation, scanning electron microscopy, and micro-Raman spectroscopy analyses indicate that the creation of uniform and sufficiently thick films with the highest degree of atomic ordering occurs at temperatures between 725 and 775°C and a gas residence of about 14 s. Notably, the same carbon deposition conditions produced crack-free and gastight YSZ films (15-20 μm) during the fabrication of SOFCs by EPD and subsequent sintering. © 2001 The Electrochemical Society. All rights reserved.