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The parameters for metal-organic chemical vapor deposition (MOCVD) processes significantly influence the properties of ZnO films, especially the flow stability of the chamber, which is caused by process parameters such as the shape of reaction chamber, the working pressure, the growth temperature, the susceptor rotational speed, the gas flow rate, and the nature of the carrier gas at inlet temperature. These parameters are the preconditions for the formation of high-quality film. Therefore, this study uses Ar as a carrier gas, diethylzinc (DEZn) as a Zn source, and H2O as an oxygen source and adopts the reaction mechanism calculated by quantum chemistry, which includes ten gas reactions and eight surface reactions. The process parameters of a specific reaction chamber model were analyzed based on the computational fluid dynamics method. This study also presents an accurate prediction of the flow regime in the reactor chamber under any operating conditions, without additional experiments, based on an analysis of a great quantity of simulation data. Such research is also significant for selecting the growth parameters relevant to production, providing a specific process growth window, narrowing the debugging scope, and providing a theoretical basis for the development of MOCVD equipment and process debugging.

This study focuses on the deposition conditions, structural and mechanical properties of Cr films obtained by magnetron sputtering with hot target, and using high power pulsed supply with pre-ionization (pulse frequency 500 Hz, duty cycle 4% in the range of averaged power from 15 to 40 W/cm 2 ). It has been found that hot target leads to a tenfold increase in the energy flux to the substrate compared to magnetron sputtering with cooled target. Intense sublimation from the target allows increasing the deposition rate of Cr films of about an order of magnitude. Moreover, the increase in the magnetron power may be accompanied by less heating of the substrates when depositing films of the same thickness. High power pulsed magnetron sputtering (HPPMS) with sublimating Cr hot target can be characterized by a combined mode in the film structure formation, leading to the formation of pores at the initial stage of growth. Cr films with a thickness of about 10 μm, obtained using a hot target, have lower surface roughness, hardness, and Young's modulus compared with sputtered Cr from a cooled target.

Here, single-phase Mn2O3 and Mn3O4 films are successfully fabricated by a facile solution process based on metal-organic decomposition (MOD), for the first time. A formulated manganese 2-ethylhexanoate solution was used as an MOD precursor for the preparation of manganese oxide films. The difference in thermal decomposition behavior of precursor solution in air and inert atmospheres was observed, indicating that the calcination atmosphere is the main factor for controlling the valence of manganese oxide films. Significantly, the solution-coated films on substrates are found to be transformed into single-phase Mn2O3 and Mn3O4 films when they are calcinated under air and inert atmosphere, respectively. The film crystallinity was improved with increasing calcination temperature for both Mn2O3 and Mn3O4 films. In particular, it is noted that the grains of Mn2O3 film were somewhat linearly grown in air, while those of Mn3O4 film exhibited the drastic growth in Ar with an increase of calcination temperature.

The current Canadian used nuclear fuel container (UFC) design uses a pressure‑grade carbon steel (CS) vessel with its outer surface coated with a thin layer of copper. One concern regarding the structural integrity of the UFC design is the potential internal corrosion of the CS vessel. Moisture trapped inside a UFC could condense within the gap between the hemispherical head and the cylindrical body of the vessel. The internal UFC environment will be exposed to a continuous flux of ionizing radiation arising from the decay of radionuclides trapped in the used UO2 fuel matrix. This thesis research project investigates the effects of physical and chemical solution parameters on CS corrosion, with the aim of developing a corrosion dynamics model that can be used to assess the integrity of the current Canadian UFC design with confidence. The parameters studied in this thesis project were the ratio of solution volume to surface area, pH, dissolved O2, and the presence or absence of γ-radiation. Corrosion dynamics were followed using electrochemical techniques, both conventional and non‑standard techniques developed as part of this project. The electrochemical tests were augmented with post-test surface and solution analyses to study oxides formed on corroded surfaces and to determine the dissolved metal content in the solution phase. The results of this study clearly demonstrated that CS corrosion involves many oxidation steps that lead to the formation and growth of different oxides as well as the dissolution of metal ions. The transfer of Fe atoms between metal, oxide and solution phases provides routes for developing strong systemic feedback that can induce autocatalytic reaction cycles, resulting in oscillatory behaviours that are observable under certain solution conditions. The dynamics of CS corrosion may not approach and reach only one steady state, but continue to evolve and reach different steady states, depending on solution parameters. A mechanism that can explain the CS corrosion dynamics over long time periods under a range of solution conditions has been proposed. The mathematical formulation of a model for the long-term corrosion of CS based on this mechanism has just begun. This study has shown that the corrosion dynamics in the early stages of corrosion can be easily modeled by applying classical electrochemical reaction rate equations coupled with mass transport flux equations. However, for CS in aerated solutions or other oxidizing environments, these classical equations must be formulated for the metal oxidation process rather than the reduction of solution species (oxidant) because the former process is rate determining.

Submitted by Nilton Francelosi Azevedo Neto (nilton@fc.unesp.br) on 2018-11-22T13:54:33Z No. of bitstreams: 1 Azevedo Neto- Tese POSMAT-2018.pdf: 3312025 bytes, checksum: 69a53514543bbe65b47c2fd62ddb6168 (MD5) Approved for entry into archive by Lucilene Cordeiro da Silva Messias null (lubiblio@bauru.unesp.br) on 2018-11-22T16:48:03Z (GMT) No. of bitstreams: 1 azevedoneto_nf_dr_bauru.pdf: 3312025 bytes, checksum: 69a53514543bbe65b47c2fd62ddb6168 (MD5) Made available in DSpace on 2018-11-22T16:48:03Z (GMT). No. of bitstreams: 1 azevedoneto_nf_dr_bauru.pdf: 3312025 bytes, checksum: 69a53514543bbe65b47c2fd62ddb6168 (MD5) Previous issue date: 2018-09-24 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) A motivação para este trabalho foi buscar uma melhor compreensão sobre o processo de crescimento dos filmes de óxido de cobalto pela técnica de DC magnetron sputtering reativo. Os filmes de interesse foram depositados sobre substratos de sílica amorfa (a -SiO2 ), aluminato de lantânio (LaAlO3 ) e safira - c (Al2O3- c) usando diferentes valores de potência de deposição e fluxo de oxigênio . As condições de crescimento dos filmes foram analisadas utilizando simulação computacional do processo de sputtering reativo baseada no modelo de Depla, medidas da emissão óptica das espécies presentes no plasma e monitor amento da taxa de crescimento através de uma microbalança de quartzo. Os resultados de difração de raios X mostraram que em baixa potência é obtida a fase Co3O4 espinélio, enquanto que em alta potência os filmes apresentaram a fase CoO cúbica . A s simulações computacionais do processo de sputtering reativo indicaram que , quando as potências de deposição são baixas, o processo de crescimento dos filmes ocorre com o alvo no regime “envenenado” . Em contraste, altas potencias favorece m o regime metálico do alvo. Medidas de emissão do plasma de deposição mostraram que em baixa potência de deposição a intensidade da linha de emissão do oxigênio é alta , porém com o aumento da potência sua intensidade diminui e a d a linha do cobalto aumenta. O s filmes de Co 3 O 4 depositados sobre substratos cristalinos apresentaram resultados promissores . Medidas de difração de raios X de alta resolução , utilizando radiação síncrotron , indicaram que a deposição do Co 3 O 4 sobre Al2O3 - c resultou em crescimento epitaxial na qual a direção [ 111] do cristal de Co 3 O 4 é perpendicular à superfície do substrato de safira - c (0001). Enquanto que a deposição sobre LaAlO 3 resultou em crescimento com forte textura de orientação, com as direções [220] e [400] perpendiculares à superfície dos substratos . Os espectros Raman dessas amostras apresentaram picos de vibração bem definidos e característicos da fase Co 3 O 4 e a análise do Raman polarizado do s filmes de Co 3 O 4 sobre Al 2 O 3 - c concorda m com as regras de seleção para a orientação [111] . Para os filmes c om fase Co 3 O 4 , medidas de transmitância na região do UV - Vis - NIR mostraram alta absorção na região do visível e bandas de absorção no infravermelho próximo relacionadas a transições eletrônicas dos íons de Co 2+ e Co 3+ . Para esse crescimento observou - se também resposta intensa de fotocondutividade com exc itação em 405 nm e 532 nm em 10 K. Testes preliminares de fotocatálise indicaram que os filmes de Co 3 O 4 produzidos possuem uma pequena atividade fotocatalítica para degradação do corante Rodamina B. Neste trabalho uma correlação direta entre as condições de crescimento e as mudança s de fase do s filmes foi obtida, demonstrando a versatilidade da técnica de sputtering para crescimento de filmes de óxido de cobalto para estudos científicos e aplicações tecnológicas. The motivation for this work was to obtain a better understanding of the growth process of cobalt oxides by the DC magnetron reactive sputtering technique. The films were dep osited on amorphous silica (a-SiO2), lanthanum aluminate (LaAlO3) and sapphire-c (c-Al2O3) substrates using different values of deposition power and oxygen flow. The conditions of growth of the films were analyzed using the optical analysis of the species present in the plasma and the monitoring of the growth rate through a quartz microbalance. The X-ray diffraction results showed that at lower powers the Co3O4 phase was obtained, while at high er power s the films presented the CoO cubic phase. The computational simulations of the reactive sputtering process indicated that, at low deposition power, the gro wth process of the films occurs with the target in the "poisoned" regime, while in high powers it favors the metallic regime of the target. Plasma emission measurements showed that at low deposition power the oxygen intensity is high while at high power it s intensity decreases and that of cobalt increases. The Co 3 O 4 films deposited on crystalline substrates showed promising results. High - resolution X-ray diffraction measurements using synchrotron radiation indicated that the deposition of Co3O4 on c-Al2O3 resulted in epitaxial growth , in which the direction [111] is perpendicular to the surface of the c - sapphire (0001) substrates. However, the deposition on LaAlO 3 resulted in growth with strong texture in the directions [220] and [400]. The Raman spectra of these samples showed well - defined vibration peaks characteristic of the Co3O4 phase . The polarized Raman analysis of Co 3 O 4 deposited on c-Al2O3 agrees with the selection rules for the [111] orientation, in agreement with the high resolution X-ray diffraction analysis . In the optical transmittance measurements , t he films with Co 3 O 4 phase displayed high absorption bands in the region of the visible and near - infrared . These bands are related to el ectronic transitions of the Co2+ and Co3+ ions. For these films , strong photoconductivity responses were observed for excitations at 405 nm and 532 nm at 10 K . Preliminary photocatalysis tests indicated that the Co3O4 films produced by sputtering have a small photocatalytic activity for Rhodamine B (RhB) dye degradation. Concluding , a direct correlation between the growth conditions and the phase changes of the films was obtained, demonstrating the versatility of the sputtering technique for the growth of cobalt oxide films for scientific studies and technological applications.

We have grown ZnS thin films by means of the radiofrequency (RF) magnetron sputtering technique onto c-Al2O3 and Si substrates at a temperature of 300°С. An effect of thermal annealing on air in a temperature range from 450°С to 800°С on the properties of the deposited films was studied and discussed. It was found that the annealing of the ZnS films leads to a formation both ZnSО layers with different sulfur/oxygen content and pure ZnО layers. It is evidenced by XRD data and optical transmission measurements. An analysis of the optical transmission spectra allowed determining a dependence of the band-gap energy of the films on the conditions of the thermal oxidations on air., Тонкие пленки ZnS, выращенные высокочастотным (ВЧ) распылением на c-Al2O3 и Si подложках при 300°С и проведено их термическое окисление на воздухе в интервале температур от 450°С до 800°С. Проведение отжига пленок ZnS приводит к образованию как слоев ZnSО с различным содержанием серы и кислорода, так и слоев чистого ZnО, о чем свидетельствуют результаты XRD анализа и спектры оптического пропускания. Для этих пленок с оптического пропускания была определена зависимость ширины запрещенной зоны от условий их термического окисления на воздухе., Тонкі плівки ZnS, вирощені високочастотним (ВЧ) розпилюванням на c-Al2O3 та Si підкладках при 300°С та проведено їх термічне окислення на повітрі в інтервалі температур від 450°С до 800°С. Проведення відпалу плівок ZnS приводить до утворення як шарів ZnSО з різним вмістом сірки і кисню, так і шарів чистого ZnО, про що свідчать результати XRD аналізу та спектри оптичного пропускання. Для цих плівок із оптичного пропускання була визначена залежність ширини забороненої зони від умов їх термічного окислення на повітрі.

Interface roughness is a critical parameter determining the performance of semiconductor devices. We show that a continuous wavelet transform is useful to describe not only the magnitude of the interface roughness, but also the spatial frequencies that describe the interface. We propose a simple presentation of the results that makes it convenient to compare between interfaces. In particular, an average and maximum value wavelet profile that is obtained from a series of one dimensional wavelet transforms provides a traceable and quick survey of the results. We demonstrate the wavelet transform method using both computer simulations and by applying it to experimental data obtained by electron tomography of a test sample and to a molecular layer interface. Wavelet descriptions of the interface roughness suffers less from the presence of shot noise in the experimental data than the traditional root mean square error description of interface roughness. An increase in lateral dimensions of an interface that has large features increases the content of low spatial frequencies in wavelet transforms. In comparison, the value of root mean square error increases in an untraceable manner with the same increase in lateral dimensions on the same interface. Morse wavelets with γ = 9 and β = 3 appear to be a suitable choice for applications in interface roughness measurement.

Copper is the selected material for the fabrication of nuclear fuel waste containers in Sweden, Finland and Canada due to its corrosion resistance in the anoxic aqueous environments, anticipated in deep geological repositories. A potential oxidant for copper is bisulphide produced either by the dissolution of minerals or by sulphate-reducing bacteria. The primary goals of this thesis were to determine the mechanism of corrosion of copper in bisulphide environments and to investigate the chemistry of the bentonite porewater that will ultimately be in contact with the copper container. The mechanism of sulphide film growth and the details of copper corrosion in anoxic aqueous bisulphide solutions in the presence of various groundwater anions have been investigated electrochemically. The chalcocite films were analyzed via voltammetry, electrochemical impedance spectroscopy and surface analysis. Under these conditions, growth of a coherent film occurred initially but the development of interfacial stresses led rapidly to film fracture. Upon fracture, a resistive outer chalcocite deposit formed with continued growth governed by the mass transport of bisulphide. Specific anion effects were observed with chloride, a common groundwater ion, found to maintain porosity in the chalcocite film while the oxyanions, sulphate and bicarbonate were found to suppress film growth. At high bisulphide concentrations and positive potentials growth of the outer deposit caused an apparent partial passivation of the surface, which theoretically could lead to localized film breakdown and pitting. However, the required high bisulphide concentrations are not attainable in a deep geologic repository and pitting should not occur. Bentonite porewater chemistry was successfully monitored using a novel experimental set-up. Electrochemical sensors monitoring pH, chloride concentration and the copper corrosion potential were placed both on the surface and inside of a bentonite clay disk. The results showed that the bentonite acted like a pH buffer and chloride from bulk solution adsorbed onto the montmorillonite structure. Corrosion potential measurements suggested that corrosion likely occurred via formation of a copper chloride complex or growth of a cuprite film. Data collected from these studies will be used directly by SKB via incorporation into models.

"Available online 21 November 2017", The deposition of decorative coatings is an excellent solution to modify the surface of any material, particularly the aesthetic finishing, without altering the properties of the substrate. Transition metal oxynitride films are interesting for many applications, due the simple and economic way to tune between nitride and oxide bonding. In reactive sputtering, this is done by playing with the flows of N2 and O2, leading to variations of properties (e.g. color) in different directions. In this paper, zirconium is selected as transition metal due to combination of different characteristics (color, biocompatibility, mechanical properties, corrosion resistance). The literature about Zr-O-N films reveals a confinement of chemical composition. Therefore, the aim of this work is the exploration of the deposition parameter space in order to evaluate the stability of the Zr-O-N system, i.e. verify if the chemical composition of the films still falls in the same range after variation of different deposition parameters. To do that, a series of Zr-O-N films is deposited first at different reactive flows, maintaining the remaining deposition parameters constant. The obtained films can be classified in three different groups, based on their chemical composition, crystalline structure, and film growth. These groups can be successfully explained according to the sputtering characteristics, and correlated with the mechanical properties and color of the films measured by nanoindentation and spectrophotometry receptivity. The films deposited by variation of other parameters are introduced afterwards and their characteristics are compared with the reference series., The financial support of Portuguese Foundation of Science and Technology (FCT), under the project number IF/00671/2013 is gratefully acknowledged., info:eu-repo/semantics/acceptedVersion

Controlling the semiconductor-to-metal transition temperature in epitaxial VO2 thin films remains an unresolved question both at the fundamental as well as the application level. Within the scope of this work, the effects of growth temperature on the structure, chemical composition, interface coherency and electrical characteristics of rutile VO2 epitaxial thin films grown on TiO2 substrates are investigated. It is hereby deduced that the transition temperature is lower than the bulk value of 340 K. However, it is found to approach this value as a function of increased growth temperature even though it is accompanied by a contraction along the V4+-V4+ bond direction, the crystallographic c-axis lattice parameter. Additionally, it is demonstrated that films grown at low substrate temperatures exhibit a relaxed state and a strongly reduced transition temperature. It is suggested that, besides thermal and epitaxial strain, growth-induced defects may strongly affect the electronic phase transition. The results of this work reveal the difficulty in extracting the intrinsic material response to strain, when the exact contribution of all strain sources cannot be effectively determined. The findings also bear implications on the limitations in obtaining the recently predicted novel semi-Dirac point phase in VO2/TiO2 multilayer structures. © 2018 American Chemical Society. 10 14132 14144 14132-14144

cited By 0; International audience; The nucleation and lateral growth are more and more important steps for the thin film growth of a phase (silicide, intermetallic…) when the thin film thickness is in the range or below 10 nm. It might become crucial for contact in microelectronics that are in this range of thickness for actual devices and affect the properties of contacts in different parts of the devices. For reaction between 10 nm Ni(10%Pt) and (100)Si, it was shown that NiSi grows by nucleation and lateral growth at the epitaxial θ-Ni2Si/Si interface and forms precipitates having a large aspect ratio (large diameter and small thickness) were observed. In this work, the precipitate shape as well as the shape of the different interfaces close to the triple line are reproduced by using the model of Pasichnyy and Gusak for θ-Ni2Si/Si interfaces that are either curved or straight. The deduced interfacial energies and kinetics parameters enabling to obtain the characteristics of the precipitates are discussed and compared to the ones obtained by the model of El Kousseifi et al. The conditions for mechanical equilibrium and the implication for the contact formation are discussed. © 2018 Elsevier B.V.

This paper presents a 3D multiscale simulation approach to model magnetron reactive sputter deposition of TiOx

We report an inexpensive nanoscale patterning process for epitaxial lateral overgrowth (ELOG) in AlN layers grown by metal organic vapour phase epitaxy (MOVPE) on sapphire. The pattern was produced by an inductively coupled plasma etch using a self-assembled monolayer of silica spheres on AlN as the lithographic mask. The resulting uniform 1 [small mu ]m length rod structure across a wafer showed a massive reduction in threading dislocations (TDs) when annealed at 1100 [degree]C. Overgrowing homoepitaxial AlN on top of the nanorods, at a temperature of 1100 [degree]C, produced a crack free coalesced film with approximately 4 [small mu ]m of growth, which is formed at a much lower temperature compared to that typically required for microscale ELOG. The improved crystal quality, in terms of TD reduction, of the AlN above the rods was determined by detailed weak beam (WB) electron microscopy studies and showed that the threading dislocation density (TDD) was greatly reduced, by approximately two orders of magnitude in the case for edge-type dislocations. In situ reflectance measurements during the overgrowth allowed for thickness coalescence to be estimated along with wafer curvature changes. The in situ measurements also confirmed that tensile strain built up at a much slower rate in the ELOG AlN layer compared to that of AlN prepared directly on sapphire.

Within this work we investigate synthesis conditions for the direct growth of Fe3+/H2BDC and Fe3+/H2NDC MOFs onto functionalized silicon (111) surfaces exhibiting well-defined structure and whose surface chemistry can be tailored in order to favor/direct the heterogeneous nucleation and growth of the MOFs. Growth mechanism of relevant MOFs at chosen conditions and flexible properties of MIL-88B and MIL-88C frameworks are presented as well with the assistance of post-synthesis treatment results.Regarding the system of Fe3+/H2BDC morphologies and structures of obtained layers strongly depend both on surface chemistry of grafted monolayers and also on the synthesis conditions (temperature, solution composition and reaction time). Oriented MIL-88B crystals along [001] direction is only observed onto COOH-functionalized surfaces and was found to be favored in presence of ligand excess in solution. The formation of textured MIL-101 phase along [111] direction on pyridyl and hydroxyl terminated Si surfaces is observed irrespective of the synthesis condition. Isolated MIL-101crystals with preferred orientation along [111] direction was also found on acid terminated surface at excess of metal, whereas randomly oriented MIL-101 islands are observed at ratio R≧1. In contrary, no film growth happened on methyl terminated Si surfaces. Introduction of HCl, H2O and organic weak base-triethylamine into the precursor solutions also affects the formation of MOF films with various morphologies and coverage between MIL-101 and MIL-88B on carboxylic terminated Si surfaces. Time dependence of film growth at excess of ligand (R=2) and at excess of metal (R=0.5) without and with addition of HCl indicates clearly that both of MIL-88B and MIL-101 follows a Volmer-Weber growth mode, during which, isolated three-dimensional crystals or clusters formed at initial stage and grew both laterally and vertically on the surface.As to the system of Fe3+/H2NDC, depending on the synthesis conditions including temperature, ratio of ligand to [Fe3+] and [Fe3+] concentration only one phase-MIL-88C with variable surface coverage ranging from separated hexagonal crystals to layers composed of isolated bundles of hexagonal crystallites all with preferential orientation along [001] direction was observed. Evolution of MIL-88C crystals along with crystallization time also suggests a Volmer-Weber mode.Ex-situ XRD measurements of post-treatment towards the as-synthesized layers comprised of MIL-88B and MIL-88C respectively demonstrate their flexibility during molecule desorption. Tentative in-situ XRD measurements also show the reversibility of MIL-88C framework upon ethanol uptake and release., Dans ce travail, nous étudions les conditions de synthèse pour la croissance directe des MOF Fe3 + / H2BDC et Fe3 + / H2NDC sur des surfaces de silicium fonctionnalisées (111) présentant une structure bien définie et dont la chimie de surface peut être adaptée pour favoriser / diriger la nucléation et la croissance hétérogènes Des MOF. Le mécanisme de croissance des MOF pertinents aux conditions choisies et les propriétés flexibles des cadres MIL-88B et MIL-88C sont également présentés avec l'aide des résultats du traitement post-synthèse.En ce qui concerne le système de morphologies et structures Fe3 + / H2BDC, les structures des couches obtenues dépendent fortement de la chimie de surface des monocouches greffées et aussi des conditions de synthèse (température, composition de la solution et temps de réaction). Les cristaux MIL-88B orientés sur la direction [001] sont seulement observés sur des surfaces fonctionnalisées par COOH et se sont révélés être favorisés en présence d'un excès de ligand en solution. La formation de la phase MIL-101 texturée le long de la direction [111] sur les surfaces de Si pyridyl et hydroxy-terminé est observée indépendamment de la condition de synthèse. Des cristaux MIL-101 isolés avec une orientation préférée le long de la direction [111] ont également été trouvés sur une surface terminée par acide à un excès de métal, alors que les îlots MIL-101 orientés au hasard sont observés au rapport R ≧ 1. Au contraire, aucune croissance du film ne s'est produite sur les surfaces de Si à terminaison méthyle. L'introduction de HCl, de H2O et de base faible organique -triéthylamine dans les solutions précurseurs affecte également la formation de films MOF avec différentes morphologies et couverture entre MIL-101 et MIL-88B sur des surfaces de Si à terminaison carboxylique. La dépendance temporelle de la croissance du film à un excès de ligand (R = 2) et d'un excès de métal (R = 0,5) sans et avec addition de HCl indique clairement que les deux MIL-88B et MIL-101 suivent un mode de croissance Volmer-Weber, Au cours de laquelle, des cristaux ou des grappes tridimensionnels isolés se sont formés à l'étape initiale et se sont développés latéralement et verticalement à la surface.En ce qui concerne le système de Fe3 + / H2NDC, en fonction des conditions de synthèse, y compris la température, le rapport du ligand à la concentration [Fe3 +] et [Fe3 +] seulement une phase-MIL-88C avec une couverture de surface variable allant des cristaux hexagonaux séparés aux couches composées d'isolés On a observé des faisceaux de cristallites hexagonales tous avec une orientation préférentielle le long de la direction. L'évolution des cristaux de MIL-88C avec le temps de cristallisation suggère également un mode Volmer-Weber.Les mesures ex-situ XRD du post-traitement vers les couches synthétisées constituées de MIL-88B et MIL-88C démontrent respectivement leur flexibilité lors de la désorption des molécules. Les mesures provisoires de la XRD in situ montrent également la réversibilité du cadre MIL-88C lors de l'absorption et de la libération de l'éthanol.

The networks of veins and arteries on the chorionic plate of the human placenta are analyzed in terms of Voronoi cells derived from these networks. Two groups of placentas from the United States are studied: a population cohort with no prescreening, and a cohort from newborns with an elevated risk of developing autistic spectrum disorder. Scaled distributions of the Voronoi cell areas in the two cohorts collapse onto a single distribution, indicating common mechanisms for the formation of the complete vasculatures, but which have different levels of activity in the two cohorts.