Journal articles on the topic 'Ge/Si ratios'

Germanium/Silicon (Ge/Si) ratio is a common proxy for primary mineral dissolution and secondary clay formation yet could be affected by hydrothermal and anthropogenic activities. To decipher the main controls of riverine Ge/Si ratios and evaluate the validity of the Ge/Si ratio as a weathering proxy in the Tibetan Plateau, a detailed study was presented on Ge/Si ratios in the Yarlung Tsangpo River, southern Tibetan Plateau. River water and hydrothermal water were collected across different climatic and tectonic zones, with altitudes ranging from 800 m to 5000 m. The correlations between TDS (total dissolved solids) and the Ge/Si ratio and Si and Ge concentrations of river water, combined with the spatial and temporal variations of the Ge/Si ratio, indicate that the contribution of hydrothermal water significantly affects the Ge/Si ratio of the Yarlung Tsangpo River water, especially in the upper and middle reaches. Based on the mass balance calculation, a significant amount of Ge (11–88%) has been lost during its transportation from hydrothermal water to the river system; these could result from the incorporation of Ge on/into clays, iron hydroxide, and sulfate mineral. In comparison, due to the hydrothermal input, the average Ge/Si ratio in the Yarlung Tsangpo River is a magnitude order higher than the majority of rivers over the world. Therefore, evaluation of the contribution of hydrothermal sources should be considered when using the Ge/Si ratio to trace silicate weathering in rivers around the Tibetan Plateau.

Molecular dynamics simulations using Tersoff potential were performed in order to study the evolution of the atomic packing structures, loading states on the atoms, and tensile tests, as well as the thermal properties of Si/Ge core–shell nanowires with different core–shell structures and ratios at different temperatures. Potential energy and pair distribution functions indicate the structural features of these nanowires at different temperatures. During uniaxial tensile testing along the wire axis at different temperatures, different stages including elasticity, plasticity, necking, and fractures are characterized through stress–strain curves, and Young’s modulus, as well as tensile strength, are obtained. The packing patterns and Lode–Nadai parameters reveal the deformation evolution and different distributions of loading states at different strains and temperatures. The simulation results indicate that as the temperature increases, elasticity during the stretching process becomes less apparent. Young’s modulus of the Si/Ge core–shell nanowires at room temperature show differences with changing core–shell ratios. In addition, the Lode–Nadai parameters and atomic level pressures show the differences of these atoms under compression or tension. Temperature and strain significantly affects the pressure distribution in these nanowires. The phonon density of states, when varying the composition and strain, suggest different vibration modes at room temperature. The heat capacities of these nanowires were also determined.

A low-resistance nonspiking Ohmic contact to n-GaAs is formed via solid-state reactions utilizing the Si/Pd/GaAs system. Samples with Si to Pd atomic ratios greater than 0.65 result in specific contact resistivity of the order of 10−6 Ω cm2, whereas samples with atomic ratios less than 0.65 yield higher specific contact resistivities or rectifying contacts. Rutherford backscattering spectrometry, cross-sectional transmission electron microscopy, and electron diffraction patterns show that a Pd, Si layer is in contact with GaAs with excess Si on the surface after the Ohmic formation annealing. This observation contrasts with that on a previously studied Ge/Pd/GaAs contact where Ohmic behavior is detected after transport of Ge through PdGe to the interface with GaAs. Comparing the Ge/Pd/GaAs system with the present Si/Pd/GaAs system suggests that a low barrier heterojunction between Ge and GaAs is not the primary reason for Ohmic contact behavior. Low-temperature measurements suggest that Ohmic behavior results from tunneling current transport mechanisms. A regrowth mechanism involving the formation of an n+ GaAs surface layer is proposed to explain the Ohmic contact formation.

The temperature of crystallization of amorphous semiconductor films contacted with metal film is much lower than that of isolated amorphous films. This phenomenon is called metal-enhanced crystallization. In our previous works many fractals were formed after crystallization in bilayer films Pd/Si, Au/Ge and Ag/Ge. Based on TEM observation a mechanism of random successive nucleation was proposed to simulate the fractal formation in Pd/Si films. In this paper the fractal formation in Al/Ge films with different thickness ratios of Al and Ge is reported.At first Ge and then Al were evaporated onto fresh cloven NaCl in ordinary high vacuum without breaking the vacuum. Thicknesses of Ge and Al were obtained from masses of Ge and Al used according to the formula of point evaporation source as follows:

Mid-oceanic ridge basalts (MORBs) are depleted in incompatible elements, but ridge segments far from mantle plumes frequently erupt chemically enriched MORBs (E-MORBs). Two major explanations of E-MORBs are that these basalts are generated by the melting of entrained recycled crust (pyroxenite) beneath ridges or by the melting of refertilized peridotites. These two hypotheses can be discriminated with compatible element abundances from Sc to Ge, here termed the ScGe elements. Here, we demonstrate that E-MORBs have systematically lower Ge/Si and Sc contents and slightly higher Fe/Mn and Nb/Ta ratios than depleted MORBs (D-MORBs) due to the mixing of low-degree pyroxenite melts. The Ge/Si ratio is a new tracer that effectively discriminates between melts derived from peridotite sources and melts derived from mixed pyroxenite-peridotite sources. These new data are used to estimate the distribution of pyroxenite in the mantle sources of global MORB segments.

Photonic crystals (PCs) with infiltrating liquid crystals (LCs) have many potential applications because of their ability to continuously modulate the band-gaps. Using the plane-wave expansion method (PWM), we simulate the band-gap distribution of 2D honeycomb lattice PC with different pillar structures (circle, hexagonal and square pillar) and with different filling ratios, considering both when the LC is used as filling pillar material and semiconductors ( Si , Ge ) are used in the substrate, and when the semiconductors ( Si , Ge ) are pillar material and the LC is the substrate. Results show that unlike LC-based triangle lattice PC, optimized honeycomb lattice PC has the ability to generate absolute photonic band-gaps for fabricating optical switches. We provide optimization parameters for LC infiltrating honeycomb lattice PC structure based on simulation results and analysis.

Abstract Contents of Ga and Ge in granites, rhyolites, orthogneisses and greisens of different geochemical types from the Bohemian Massif were studied using inductively coupled plasma mass spectrometry analysis of typical whole-rock samples. The contents of both elements generally increase during fractionation of granitic melts: Ga from 16 to 77 ppm and Ge from 1 to 5 ppm. The differences in Ge and Ga contents between strongly peraluminous (S-type) and slightly peraluminous (A-type) granites were negligible. The elemental ratios of Si/1000Ge and Al/1000Ga significantly decreased during magmatic fraction: from ca. 320 to 62 and from 4.6 to 1.2, respectively. During greisenization, Ge is enriched and hosted in newly formed hydrothermal topaz, while Ga is dispersed into fluid. The graph Al/Ga vs. Y/Ho seems to be useful tool for geochemical interpretation of highly evolved granitoids.

ABSTRACTGe-Si alloy nanoparticles (NPs) covering the full range of compositions were studied in regard to their suitability as semiconducting channel layer in thin-film transistors (TFTs). Special focus is given to the influence of annealing and encapsulation techniques on the contact and channel properties. Therefore, electrical characterization methods separating contact from channel characteristics are highlighted and applied. It is demonstrated that appropriate passivation of the nanoparticle surfaces can improve the Ion/Ioff ratios by modulation of the density of free charge carriers and also can suppress hysteresis effects. Ge-rich NP alloys can generally be passivated more effectively regardless if passivation is done with solution-processed poly(methyl methacrylate) (PMMA) or by aluminum oxide (Al2O3) from Atomic Layer Deposition (ALD). Sufficient annealing improves the contact formation between aluminum electrodes and Ge-Si particles by modification of charge injection. The presented analysis leads to a better understanding interface and surface effects in porous nanoparticle semiconductors for application in TFT devices.

A single-wafer multiprocessing technology has been developed based on the use of lamp heating and remote microwave plasma process energy sources for fabrication of in-situ-doped homoepitaxial Si and heteroepitaxial Si/GexSi1−x multilayer structures via chemical-vapor deposition. Some effective low-temperature (650°–800°C) processes were developed for in-situ pre-epitaxial growth surface cleaning. These chemical cleaning processes employ GeH4 + H2 or GeH4 + H2 + (HF or HCl) gas mixtures with very small GeH4-to-H2 gas flow rate ratios. Multilayer heteroepitaxial structures with controlled doping and Ge fractions consisting of strained Ge4Si1−x layers were fabricated and characterized.

We studied the thermo-elastic properties of Ru2FeZ (Z[Formula: see text]=[Formula: see text]Si, Ge, Sn) Heusler alloys within the framework of density functional theory. Thermo-elastic properties corresponding to elastic modulus, anisotropy, phase stability, elastic wave velocities, thermal stability, Debye temperature, melting temperature, thermal conductivity and formation energy are calculated. The elastic constants C[Formula: see text] predict the structural and dynamical stabilities while the formation energies show thermal stability of the alloys at 0 K. Pugh’s and Poisson’s ratios display the ductile nature of alloys. All alloys are anisotropic and we also observed that Ru2FeSn is the hardest material than Ru2FeSi and Ru2FeGe. Moreover, longitudinal mode of vibrations are also observed and are maximum along [100], [110] and [111] directions than the transverse mode of vibrations.

The effect of solutal Marangoni convection on flow instabilities in the presence of thermal Marangoni convection in a Si-Ge liquid bridge with different aspect ratios As has been investigated by three-dimensional (3D) numerical simulations under zero gravity. We consider a half-zone model of a liquid bridge between a cold (top plane) and a hot (bottom plane) disks. The highest Si concentration is on the top of the liquid bridge. The aspect ratio (As) drastically affects the critical Marangoni numbers: the critical solutal Marangoni number (under small thermal Marangoni numbers (MaTAs≲1800)) has the same dependence on As as the critical thermal Marangoni number (under small solutal Marangoni numbers (400≲MaCAs≲800)), i.e., it decreases with increasing As. The azimuthal wavenumber of the traveling wave mode increases as decreasing As, i.e., larger azimuthal wavenumbers (m=6,7,11,12, and 13) appear for As=0.25, and only m=2 appears when As is one and larger. The oscillatory modes of the hydro waves have been extracted as the spatiotemporal structures by using dynamic mode decomposition (DMD). The present study suggests a proper parameter region of quiescent steady flow suitable for crystal growth for smaller aspect ratios of the liquid bridge.

Abstract. Silicon (Si) released as H4SiO4 by weathering of Si-containing solid phases is partly recycled through vegetation before its land-to-rivers transfer. By accumulating in terrestrial plants to a similar extent as some major macronutrients (0.1–10% Si dry weight), Si becomes largely mobile in the soil-plant system. Litter-fall leads to a substantial reactive biogenic silica pool in soil, which contributes to the release of dissolved Si (DSi) in soil solution. Understanding the biogeochemical cycle of silicon in surface environments and the DSi export from soils into rivers is crucial given that the marine primary bio-productivity depends on the availability of H4SiO4 for phytoplankton that requires Si. Continental fluxes of DSi seem to be deeply influenced by climate (temperature and runoff) as well as soil-vegetation systems. Therefore, continental areas can be characterized by various abilities to transfer DSi from soil-plant systems towards rivers. Here we pay special attention to those processes taking place in soil-plant systems and controlling the Si transfer towards rivers. We aim at identifying relevant geochemical tracers of Si pathways within the soil-plant system to obtain a better understanding of the origin of DSi exported towards rivers. In this review, we compare different soil-plant systems (weathering-unlimited and weathering-limited environments) and the variations of the geochemical tracers (Ge/Si ratios and δ30Si) in DSi outputs.

Abstract. Silicon (Si) released as H4SiO4 by weathering of Si-containing solid phases is partly recycled through vegetation before its land-to-rivers transfer. By accumulating in terrestrial plants to a similar extent as some major macronutrients (0.1–10% Si dry weight), Si becomes largely mobile in the soil-plant system. Litter-fall leads to a substantial reactive biogenic silica pool in soil, which contributes to the release of dissolved Si (DSi) in soil solution. Understanding the biogeochemical cycle of silicon in surface environments and the DSi export from soils into rivers is crucial given that the marine primary bio-productivity depends on the availability of H4SiO4 for phytoplankton that requires Si. Continental fluxes of DSi seem to be deeply influenced by climate (temperature and runoff) as well as soil-vegetation systems. Therefore, continental areas can be characterized by various abilities to transfer DSi from soil-plant systems towards rivers. Here we pay special attention to those processes taking place in soil-plant systems and controlling the Si transfer towards rivers. We aim at identifying relevant geochemical tracers of Si pathways within the soil-plant system to obtain a better understanding of the origin of DSi exported towards rivers. In this review, we compare different soil-plant systems (weathering-unlimited and weathering-limited environments) and the variations of the geochemical tracers (Ge/Si ratios and δ30Si) in DSi outputs. We recommend the use of biogeochemical tracers in combination with Si mass-balances and detailed physico-chemical characterization of soil-plant systems to allow better insight in the sources and fate of Si in these biogeochemical systems.

A CMOS compatible, direct bandgap material for optical interconnects can be obtained by alloying Ge with Sn 1, applying tensile stress to Ge 2 or both 3. Lasing in GeSn was demonstrated in 2015 4 by Wirths et al., followed in 2020 by electrically pumped lasing up to 100K 5 and, in 2022, optically pumped lasing at room temperature 6,7. In-situ doped SiGeSn might offer high dopant incorporation, while delivering good electronic confinement, improving thereby the performances of devices. Such doped layers can be used in photodetectors 8–10, light-emitting diodes 11–13 and modulators 14,15 operating at wavelengths higher than 1.55 µm, enabling their use in future CMOS compatible lab-on-a-chip devices with integrated light sources 5,16,17. The in-situ doping of SiGeSn was compared to that of GeSn. All layers were grown at 349 °C, 100 Torr in a 200 mm Epi Centura 5200 RP-CVD tool from Applied Materials. Ge strain relaxed buffers were used to accommodate the lattice mismatch between (Si)GeSn and the Si substrates 18. The F(Ge2H6)/F(H2), F(Si2H6)/F(H2) and the F(SnCl4)/F(H2) Mass-Flow Ratios (MFRs) were constant at 7.92x10-4, 1.25x10-3, and 4.69x10-5, respectively. In-situ doped SiGeSn Growth Rates (GRs), shown in Figure 1 (a), were around 30 nm min.-1. They were below that of GeSn:B and GeSn:P (40 nm min.-1). The latter significantly increased for high dopant flows. Meanwhile, SiGeSn:B GR slightly increased and SiGeSn:P GR decreased as the dopant flow increased. B2H6 and PH3 might have opened surface sites for GeSn and SiGeSn:B, while the formation of gas phase intermediates might have reduced the SiGeSn:P GR. Interestingly, the surface quality improved significantly for in-situ doped SiGeSn, reaching the same quality as that of GeSn for high dopant flows, as shown in Figure 1 (b). Surfaces had RMS roughness values below 0.40 nm, close to that of GeSn, with a full surface cross-hatch recovery. There was, for in-situ doped GeSn, a Sn content reduction for high dopant flows (Figure 1 (c)+(d)) most likely because SnCl4 was mass-transport limited19 and not impacted by a larger amount of open surface sites. The influence of dopants on the layer composition was even more pronounced in SiGeSn:B. Si/Sn ratios of 3.5, with Si contents of up to 25%, were obtained, which should result in improved electrical confinement. The formation of Si and Ge gas phase intermediates might explain why Sn contents were higher, in SiGeSn:P, for high PH3 flows. Such insights should yield better control of Si and Sn contents in stacks for optical or electronic purposes. Electrically active carrier concentrations c active of the order of 2x1020 cm-3 were achieved in SiGeSn:B (Figure 1 (e)). These were seven times higher than the 3x1019 cm-3 obtained for GeSn:B. For GeSn:P, c active was likely limited by the formation of SnmPnV nanoclusters. It was at most 7x1019 cm-3 (Figure 1 (f)). Four times higher c active values were obtained for SiGeSn:P with at most 3x1020 cm-3. No decrease of c active was observed for high PH3 flows in SiGeSn:P. This might have been due to the formation of fewer SnmPnV nanoclusters. Such c active values and better electrical confinement were used to fabricate (Si)GeSn based photodiodes with improved electroluminescent integrated intensity compared to photodiodes with doped Ge contact layers. Gassenq, A. et al. Appl. Phys. Lett. 109, 242107 (2016). Elbaz, A. et al. Nat. Photonics 14, 375–382 (2020). Chrétien, J. et al. ACS Photonics 6, 2462–2469 (2019). Wirths, S. et al. Nat. Photonics 9, 88–92 (2015). Zhou, Y. et al. Optica 7, 924 (2020). Chrétien, J. et al. Appl. Phys. Lett. 120, 051107 (2022). Bjelajac, A. et al. Opt. Express 30, 3954 (2022). Li, X. et al. Photonics Res. 9, 494 (2021). Zhou, H. et al. Opt. Express 28, 10280 (2020). Wu, S. et al. IEEE J. Sel. Top. Quantum Electron. 28, 1–9 (2022). Stange, D. et al. Optica 4, 185 (2017). Oehme, M. et al. IEEE Photonics Technol. Lett. 26, 187–189 (2014). Schwartz, B. et al. Opt. Lett. 40, 3209 (2015). Bertrand, M. et al. 2020 IEEE Photonics Conference (IPC) 1–2 (IEEE, 2020). Zhou, H. et al. Opt. Express 28, 34772 (2020). Casiez, L. et al. 2020 IEEE Photonics Conference (IPC) 1–2 (IEEE, 2020). Soref, R. Nat. Photonics 4, 495–497 (2010). Hartmann, J. M. & Aubin, J. J. Cryst. Growth 488, 43–50 (2018). Margetis, J. et al. Vac. Sci. Technol. A 37, 021508 (2019). Figure 1

AbstractThe results of an NQR study on the MCl4 complexes (M = Si, Ge, Sn) with organic heteroatom ligands (including those containing several coordination centers) are summarized: chloroanhydrides of unsaturated, aromatic and heteroaromatic carboxylic acids; alkylarylethers, ketones, aryldichlorophosphates, nitrogen-containing compounds, etc. The octahedral or trigonal-bipyramidal structure of these complexes has been established, and the factors influencing the formation and structure of such complexes (component ratio, character of ligand and M atom) have been analyzed. The structure of several complexes may vary with time or depend on the crystallization condition of the system. Some of these results indicate coordination isomerism. The quantitative ratios between the 35Cl NQR frequency shifts of ligand and axial Sn-Cl bonds in trigonal-bipyramidal RCOCl • SnCl4 complexes relative to the initial component frequencies have been found

Photoemission intensities from core levels derived from surface and bulk atoms of a solid exhibit oscillations as a function of the excitation photon energy. These oscillations cannot be described by the classical layer attenuation model, which has been the basis for intensity analysis and quantitative structural modeling in a number of studies. The physics responsible for these oscillations is the extended photoemission fine structure (EPFS) above the core level absorption edge, which contains structural information in regard to surface bond lengths. The present paper examines in detail this phenomenon for the Si 2p core level of the Si (111)−(7×7) surface. The EPFS is found to modulate the surface-to-bulk Si 2p core level intensity ratios up to ~50%; thus, structural models based on a surface-to-bulk intensity ratio analysis using the classical layer attenuation model at a few photon energies may suffer large errors. This EPFS may be responsible for the ongoing debate in the literature over the assignment of the surface core levels to structural features on both the (111) and (100) surfaces of Si and Ge. This dilemma is resolved for the (7×7) surface. Using the usual three-component fit of the Si 2p core level (a bulk component and two surface components, S1 and S2), the EPFS signals from the individual components are separately analyzed. The results show the S2 component to be derived from adatom emission. The S1 component is unresolved, and represents emission from several different types of atoms in the top double layer of the (7×7) reconstruction.

Abstract We report on the synthesis of ternary SiGeSn nanocrystals (NCs) produced via nonthermal plasma synthesis from silane (SiH4), germane (GeH4), and tetramethylstannane (Sn(CH3)4) precursor sources. Detailed structural, chemical, and vibrational analyses show that all three elements are incorporated both on the NC surface and within the NC core. Incorporation of Sn into the NC core is realized using a secondary injection of SiH4 and GeH4 precursor gases in the after-glow region of the plasma, which kinetically traps Sn in the core. We demonstrate compositional tunability of the SiGeSn NCs in which the Si and Ge ratios can be varied broadly at low Sn concentrations. We also show tunability of the Sn content up to ∼2 atomic percent as revealed by ICP-MS analysis. More generally, this report demonstrates how nonthermal plasma synthesis can be used to produce metastable ternary nanostructured alloys involving thermodynamically insoluble constituents.

Film stress and refractive index play an important role in the fabrication of suspended waveguides. SiO2 waveguides were successfully fabricated on multiple substrates including Si, Ge, and Al2O3 wafers; the waveguides were deposited using inductively coupled plasma chemical vapor deposition at 100 °C. The precursor gases were SiH4 and N2O at 1:3 and 1:9 ratios with variable flow rates. The occurrence of intrinsic stress was validated through the fabrication of suspended SiO2 bridges, where the curvature of the bridge corresponded to measured intrinsic stress, which measured less than 1 µm thick and up to 50 µm in length. The flow rates allow film stress tunability between 50 and −65 MPa, where a negative number indicates a compressive state of the SiO2. We also found that the gas ratios have a slight influence on the refractive index in the UV and visible range but do not affect the stress in the SiO2 bridges. To test if this method can be used to produce multi-layer devices, three layers of SiO2 bridges with air cladding between each bridge were fabricated on a silicon substrate. We concluded that a combination of low temperature deposition (100 °C) and photoresist as the sacrificial layer allows for versatile SiO2 bridge fabrication that is substrate and refractive index independent, providing a framework for future tunable waveguide fabrication.

The photonic energy bands of body centered cubic photonic crystals formed from SiO2, GaP, Si, InAs, GaAs, InP, Ge and BaSrTiO3 dielectric spheres drilled in air and air holes drilled in these dielectric mediums were calculated using the plane wave expansion method. The filling factor for each dielectric material was changed until a complete energy gap was obtained and then the density of states was calculated. There were no complete band gaps for air spheres drilled in these eight dielectric mediums. The lattice constants were determined by using wavelengths in the region . The variation of the band gap widths with the filling factor and the variation of gap width to midgap frequency ratios with dielectric contrast were investigated. The largest band gap width of 0.021 for normalized frequency was obtained for GaP for the filling factor of 0.0736. The mode filed distributions were obtained by guiding a telecommunication wave with wavelength through a photonic cell formed from GaP spheres in air with a filling factor of 0.0736 for transverse electric and magnetic modes.

The photonic energy bands of body centered cubic photonic crystals formed from SiO2, GaP, Si, InAs, GaAs, InP, Ge and BaSrTiO3 dielectric spheres drilled in air and air holes drilled in these dielectric mediums were calculated using the plane wave expansion method. The filling factor for each dielectric material was changed until a complete energy gap was obtained and then the density of states was calculated. There were no complete band gaps for air spheres drilled in these eight dielectric mediums. The lattice constants were determined by using wavelengths in the region . The variation of the band gap widths with the filling factor and the variation of gap width to midgap frequency ratios with dielectric contrast were investigated. The largest band gap width of 0.021 for normalized frequency was obtained for GaP for the filling factor of 0.0736. The mode filed distributions were obtained by guiding a telecommunication wave with wavelength through a photonic cell formed from GaP spheres in air with a filling factor of 0.0736 for transverse electric and magnetic modes.

Over the last few decades, MOSFET architectures have evolved from planar to 3D structures (FinFET and, more recently, gate-all-around and Forksheet devices) to improve the channel control at very scaled dimensions. In this framework, highly doped conformal Si1-xGex epitaxial films are used for source/drain (S/D) regions in pMOS devices to form ohmic metal-semiconductor contacts with low specific contact resistivities (ρc). Boron is the main p-type dopant in Si1-xGex thanks to its high active concentration (~ 1×1021 at./cm3) for Ge concentrations of ~ 50 at.% [1]. For higher Ge/Si ratios, gallium is considered a promising doping element due to its higher solid solubility in Ge compared with boron. However, a strong Ga surface segregation is reported to occur during the epitaxy of in situ doped Si1-xGex, leading to a Ga-rich second phase at the epilayer surface [2]. In films grown at temperatures ≥ 450°C, the Ga surface segregation limits the bulk Ga concentration ([Ga]chem) to 1×1018 at./cm3 [3]. This low doping level results in inferior electrical properties for current MOSFET applications. Models in the literature [4] indicate that, at sufficiently low temperature, dopant segregation is limited by surface kinetic mechanisms. Thus, the segregation ratio could be controlled by changing the process temperature. Based on this approach, low temperature, Si2H6 + Ge2H6 based processes with improved Ga incorporation were developed [5]. In this contribution, we report on novel in situ Ga doped Si1-xGex epitaxial layers grown at temperatures ≤ 400°C. Using a HCl surface clean, necessary to avoid the SIMS Ga decay from the surface which can mask the real concentration profile [3], Ga box-shaped profiles with concentrations above 1×1020 at./cm3 are found (Fig. 1). Two growth temperatures are compared: 400°C and 350°C. For each temperature, variable Ga precursor (tri-tert-butyl gallium) flows (fTTBGa) were used. A reduction in the growth temperature enhances the Ga incorporation, as evidenced from the two SEM morphology inspections displayed in Fig. 1. Here, two samples with a similar bulk [Ga]chem of ~ 6 ×1019 at./cm3, as measured by SIMS, exhibit either a clustered or smooth surface depending on the deposition temperature applied. This improved Ga incorporation allows for systematic studies of in situ Ga doping on the structural and electrical properties of Si1-xGex. In both series of samples, the layer resistivities (ρ) follow a similar trend, characterized by a steep decrease at smaller fTTBGa and a plateau for higher flows (Fig. 2). The lowest ρ values are found for the layers grown at 350°C. This denotes that different saturation levels in the active Ga concentration ([Ga]act) exist for the process conditions used here. In a similar way to what is typically observed for B doping, an increase in the Ga doping level causes a boost in epilayer growth rate. This growth rate trend saturates simultaneously with ρ, suggesting that the phenomenon is linked to the level of incorporated substitutional Ga atoms. In addition, the resulting Ge concentrations of the Si1-xGex layers are found to increase with Ga concentration. From HR-XRD analysis, strain-relaxation is also found to progressively increase with the TTBGa flow and so the incorporated Ga may not be fully active. For this reason, X-ray absorption fine structure spectra (XAFS) were acquired at the Ga K-edge on Si0.4Ge0.6:Ga and Ge:Ga epilayers with the results obtained reported in Fig.3. Based on comparative analysis of the first coordination Ga shell with DFT simulation results, Ga dopants appear to be placed in substitutional positions for both materials. Furthermore, a shorter nearest-neighbors distance is measured for Ga in Si0.4Ge0.6 compared to Ge, indicating a difference in the local strain associated to the dopant for the two considered matrixes. [1] R. Loo et al., “Processing Technologies for Advanced Ge Devices,” ECS J. Solid State Sci. Technol., vol. 6, no. 1, pp. P14–P20, 2017. [2] J. Margetis et al., “Epitaxial Growth of Ga-doped SiGe for Reduction of Contact Resistance in finFET Source/Drain Materials,” ECS Trans., vol. 93, no. 1, pp. 7–10, 2019. [3] G. Rengo et al., “B and Ga Co-Doped Si1−xGex for p-Type Source/Drain Contacts,” ECS J. Solid State Sci. Technol., vol. 11, no. 2, 024008, 2022. [4] C. B. Arnold and M. J. Aziz, “Unified kinetic model of dopant segregation during vapor-phase growth,” Phys. Rev. B - Condens. Matter Mater. Phys., vol. 72, no. 19, 195419, 2005. [5] A. Y. Hikavyy et al., “Cutting-Edge Epitaxial Processes for Sub 3 Nm Technology Nodes: Application to Nanosheet Stacks and Epitaxial Wrap-Around Contacts,” ECS Trans., vol. 104, no. 4, pp. 139–146, Oct. 2021. Figure 1

SiO2−GeO2 and Al2O3−TiO2 mixed oxide powders were synthesized using a counterflow diffusion flame burner. SiCl4, GeCl4, Al(CH3)3, and TiCl4 were used as source materials for the formation of oxide particles in hydrogen-oxygen flames. In situ particle sizes were determined using dynamic light-scattering. Powders were collected using two different methods, a thermophoretic method (particles are collected onto carbon coated TEM grids) and an electrophoretic method (particles are collected onto stainless steel strips). Their size, morphology, and crystalline form were examined using a transmission electron microscope and an x-ray diffractometer. A photomultiplier at 90° to the argon ion laser beam was used to measure the light-scattering intensity. The formation of the mixed oxides was investigated using Si to Ge and Al to Ti ratios of 3:5 and 1:1, respectively. Heterogeneous nucleation of the SiO2 on the surface of the GeO2 was observed. In Al2O3−TiO2 mixtures, both oxide particles form at the same temperature. X-ray diffraction analysis of particles sampled at temperatures higher than 1553 K showed the presence of rutile, γ–Al2O3, and aluminum titanate. Although the particle formation process for SiO2−GeO2 is very different from that for Al2O3−TiO2, both mixed oxides result in very uniform mixtures.

We have studied structure and electrical properties of Si1−YGeY:H films deposited by low-frequency plasma-enhanced chemical vapor deposition over the entire composition range from Y = 0 to Y = 1. The deposition rate of the films and their structural and electrical properties were measured for various ratios of the germane/silane feed gases and with and without dilution by Ar and by H2. Structure and composition was studied by Auger electron spectroscopy (AES), secondary ion mass spectroscopy (SIMS), and Fourier transform infrared (FTIR) spectroscopy. Surface morphology was characterized by atomic force microscopy (AFM). We found that the deposition rate increased with Y, maximizing at Y = 1 without dilution. The relative rate of Ge and Si incorporation is affected by dilution. Hydrogen preferentially bonds to silicon. Hydrogen content decreases for increasing Y. In addition, optical measurements showed that as Y goes for 0 to 1, the Fermi level moves from mid gap to the conduction band edge; i.e., the films become more n-type. No correlation was found between the pre-exponential and the activation energy of conductivity. The behavior of the conductivity γ-factor suggests a local minimum in the density of states at E ≈ 0.33 eV for the films grown with or without H-dilution and E ≈ 0.25 eV for the films with Ar dilution.

Abstract Ab initio determination of the electric field gradient (EFG) tensors at halogen and other centres ena-bled determination of the nuclear quadrupole coupling constants (NQCC) for a diverse set of axially symmetric (C3v , C∞v, D∞h and other symmetries) inorganic and organic molecules, where the heavy ele-ments are Cl, Br, and I with C, Si, Ge, and Sn hydrides. The latter elements are in an approximately tetrahedral environment. The study presents results at a standardised level of calculation, triple-zeta in the valence space (TZV) plus polarisation functions (TZVP) for the equilibrium geometry stage; all-electron MP2 correlation is included in all these studies. f-Orbital exponents were optimised for both Br and I centres in the methanes; the atomic populations of the f-orbital components are very small for the Br-and I-atoms, confirming their role as polarisation functions rather than having any bonding character. The EFG are determined at equilibrium with the TZVP basis set, except Sn and I centres where the basis set is TZV + MP2. For the bromo and iodo compounds, especially the latter, it is essential to allow for core polarisation, by decontraction of the p,d-functions. This is conveniently done by initial optimization of the structure with a partly contracted basis, followed by reestablishment of the equilibrium structure with the decontracted basis. A close correlation of the observed (microwave spectral) data with the calculations was observed, using the 'best' values for the atomic quadrupole moments for Cl, Br, and I; thus there seems no need to postulate that the value of QBr for 79Br and 81Br are in error. The SCF and MP2 wave-functions were converted into localised molecular orbitals by the Boys Method. This allowed a study of the differing s/p/d-hybridisation ratios, and the centroid positions, to be compared with the quadrupole coupling constants. The charge distributions for the atoms were converted into local bond dipoles, which in turn are correlated with the electronegativity differences of the bonded atoms.

Our aim was to assess the feasibility of the Low Temperature Selective Epitaxial Growth of tensile-Si:P (for Raised Sources and Drains in n-type FETs). Ideally, we would like to have high amounts of tensile strain and low resistivities in t-Si:P layers grown at 550°C, with (i) mainstream Si2H6 + PH3 gases for the non-selective deposition of t-Si:P and (ii) HCl + GeH4 for the selective etches of amorphous Si:P versus monocrystalline Si:P (to have selectivity on patterned wafers). In Ref (1), we focused on deposition in such cyclic processes. Thanks to (i) high F(PH3)/(2*F(Si2H6)) Mass-Flow Ratios (MFR), (ii) a reduction of the H2 carrier flow, from the reference value of a few tens of standard liters per minute down to 1/5th of it and (iii) a chamber pressure increase, from 20 Torr up to 90 Torr, we succeeded in dramatically increase [P]subst. and reach values as high as 7.9% in t-Si:P layers. 40 Torr was the best pressure in order to simultaneously have (i) a high substitutional P concentration (6.3%), (ii) a reasonable growth rate (5.5 nm min.-1) and (iii) a low electrical resistivity (0.41 mOhm. cm), without being hampered by a layer uniformity that would be too degraded to be of use in actual devices. Those t-Si:P layers, grown with a MFR of 0.46, were of superior crystalline quality and smooth. We have otherwise shown in Ref. (2) that it was possible, thanks to (i) a reduced H2 carrier flow, (ii) a low HCl mass-flow and (iii) a relatively high GeH4 mass-flow, to etch away mono-cristalline t-Si:P at temperatures close to 550°C We have thus evaluated the Cyclic Deposition / Etch (CDE) of t-Si:P at 550°C. Deposition occurred at 40 Torr with Si2H6 + GeH4, while (selective) etching was conducted at 90 Torr with HCl + GeH4. Pressure was ramped up or down with a 5 Torr / s slope. 15s pure HCl etchings, also at 90 Torr, were sometimes used after HCl + GeH4 etchings to remove surface Ge atoms. We first evaluated, for 10 cycles CDE processes, the impact of the HCl + GeH4 etch duration on the t-Si:P thickness and the substitutional P concentration. The deposition time / cycle was always 60s. As expected, the t-Si:P thickness decreased more or less linearly as the HCl + GeH4 etch duration / cycle increased, from ~ 50 nm for 0s down to 20-25 nm for 60s (Fig. a). Meanwhile, the “apparent” substitutional P concentration and thus the tensile strain decreased less and less, as the HCl + GeH4 etch duration/cycle increased, when using high flows of pure HCl at the end of each cycle to get rid of excess Ge atoms (from 6.2% for 0s down to 2.0% for 60s in the most favorable configuration; Fig. b). Such a tensile strain loss was shown by SIMS to be due to (i) less and less P atoms and (ii) more and more Ge atoms being present in the Si lattice as the HCl + GeH4 etch duration/cycle increased (from 6.2% and 0% for 0s down to/up to 4.4% and 5.5% for 60s; Fig. c). The surface haze of CDE-grown layers was otherwise ~ 2 times higher than that of layers grown without etchings and the electrical resistivity slightly increased with the HCl + GeH4 etch duration/cycle (from 0.38 mOhm.cm for 0s up to 0.42 mOhm.cm for 60s). Thanks to the use of 10 cycles CDE processes with various HCl + GeH4 etch durations on bulk and SiN-covered Si substrates, we then showed that an etch selectivity of ~ 6 could be expected, for a-Si:P over t-Si:P, on patterned wafers (Fig. d). The presence of numerous nuclei on SiN-covered substrates nominally free of any bi-dimensional a-Si:P layers was evidenced by haze measurements, however, hinting at a lower effective selectivity. We then switched over to patterned SOI wafers with gates. We succeeded, with 7 cycles CDE processes, in having almost full selectivity with 60s depositions and 40s etches / cycle, respectively (Fig. e). Maybe because there was a mix of a-Si:P and t-Si:P regions on such wafers, we had almost the same deposited t-Si:P thickness / CDE cycle (4.1 – 4.2 nm) whatever the HCl + GeH4 duration / cycle in the 15s – 40s range (Fig. f). Meanwhile, there was a gradual disappearance of a-Si:P on dielectrics as that etch duration increased. [1] J.M. Hartmann and J. Kanyandekwe, J. Cryst. Growth 582, 126543 (2022). [2] J.M. Hartmann and M. Veillerot, Semicond. Sci. Technol. 35, 015015 (2020). Figure 1

With the ever-growing technology industry and the need for more sustainable energy, the race to develop better, more efficient, renewable materials for lithium ion batteries is at the forefront of research. Metal oxide materials for use as electrodes in lithium batteries have been promising in recent years, transition metal oxides are favourable due to their low cost and nanostructured metal oxides exhibit encouraging electrochemical properties.1-2 Photonic crystal structures, more specifically inverse opal (IO) structures, are porous, highly interconnected structures which have proven to have advantageous benefits such as increased surface area and lower ion diffusion distances.3 In this work we combine TiO2 and GeO2 in solution phase in two ratios, 2:1 and 5:1 in favour of TiO2. Titanium oxides have high working potentials, higher than graphite which is most commonly used today. TiO2 has previously shown excellent long life cyclability and has shown little structural strain during the lithiation/delithiation process.4 Germanium has a high theoretical capacity of 1384 mAh/g and high electrical conductivity however it is expensive for use as an anode.5 Previous reports have shown that by nano-structuring GeO2 into an inverse opal structure, it can behave like pure germanium during cycling beyond the initial reduction and lithitation cycles.6 By combining both materials, we were able to achieve high capacity values for both ratios, 3 times the capacity of titanium IOs on their own. Work is ongoing to investigate the optimal cost to benefit ratio of the TiO2/GeO2 composites. Initial capacity results showcase high capacity retention and voltage stability. Reddy, M. V.; Subba Rao, G. V.; Chowdari, B. V. R., Metal Oxides and Oxysalts as Anode Materials for Li Ion Batteries. Chemical Reviews 2013, 113 (7), 5364-5457. Wu, H. B.; Chen, J. S.; Hng, H. H.; Wen Lou, X., Nanostructured metal oxide-based materials as advanced anodes for lithium-ion batteries. Nanoscale 2012, 4 (8), 2526-2542. Armstrong, E.; O'Dwyer, C., Artificial opal photonic crystals and inverse opal structures – fundamentals and applications from optics to energy storage. Journal of Materials Chemistry C 2015, 3 (24), 6109-6143. McNulty, D.; Carroll, E.; O'Dwyer, C., Rutile TiO2 Inverse Opal Anodes for Li-Ion Batteries with Long Cycle Life, High-Rate Capability, and High Structural Stability. Advanced Energy Materials 2017, 7 (12), 1602291. Zhang, Q.; Chen, H.; Luo, L.; Zhao, B.; Luo, H.; Han, X.; Wang, J.; Wang, C.; Yang, Y.; Zhu, T.; Liu, M., Harnessing the concurrent reaction dynamics in active Si and Ge to achieve high performance lithium-ion batteries. Energy & Environmental Science 2018, 11 (3), 669-681. McNulty, D.; Geaney, H.; Buckley, D.; O'Dwyer, C., High capacity binder-free nanocrystalline GeO2 inverse opal anodes for Li-ion batteries with long cycle life and stable cell voltage. Nano Energy 2018, 43, 11-21. Figure 1. (a) SEM image of a TiO2/GeO2 inverse opal (b) SEM image of TiO2/GeO2 IOs with EDX mapping overlay indicating position of titanium (green) and germanium (red). (c) and (d) Charge discharge profiles at 150 mA/g for the first 100 cycles for the 2:1 ratio and 5:1 ratio respectively.(e) Rate capability test for both ratios with specific currents ranging from 75 mA/g-450 mA/g. Figure 1

(francuski) Mena grandit et fut ?lev?e dans la maison de ses parents (1368-1386). La plus belle partie de sa jeunesse elle passa comme ?pouse de Djurdje II Stracimirovic et dans un r?gne autonome sur Z?ta au nom de son fils mineur Balsa (1403-1411). Son ?ge m?r elle consacra ? son deuxi?me mari, duc Sandalj (1411-1435). Les derni?res ann?es de sa vie elle uecnt comme veuve (1435-1443) jusqu'? sa mort en ?ge de soixante-quinze ans. De toutes ces p?riodes notre attention fut uniquement fix?e, en vue des mat?riaux ?dits et in?dits d'archiv? ? Kotor, et ? Raguse (Dubrovnik), ? son veuvage pendant lequel elle avait montr?, en d?pits de son ?ge, une ?nergie impressionnante. C'est surtout son engagement en mati?res de finance qui est m?rite de notre admiration. Elle prenait des int?r?ts de la somme que Sandalj avait d?pos? sous son nom et aussi elle-m?me, elle d?posait de l'argent et des valeurs diff?rentes ? Dubrovnik et ? Kotor. Si elle n'arrivait pas ? faire tout elle-m?me, elle le faisait par ses employ?s (?l?ves, notaires), envoy?s et confidents. Une partie de l'argent gagn? en ces op?rations bancaires elle utilisait aussi pour son progr?s spirituel: elle fondait des ?glises, reconstruisait celles qui ?taient vieilles et en mauvais ?tat, s'occupait des moines et jouissait en lisant la litt?rature monastique et autre, elle gardait des reliques de saints et menait des longues et int?ressantes conversations avec l'abb? Nikandar sur les questions en ce temps-l? fr?quemment disput?es: sur les questions d'aum?ne, de monachisme, de la vie c?nobite et de la vie anachor?te. Comme les autres princesses serbes (m?re Milica, Mena Serska, qui est devenue plus tard en religion Jefimija et la reine Mena Anzujska) elle aussi a eu la vie pleine de succ?s d'une femme tr?s travaillante, tr?s intelligente, qui avait en plus une tr?s bonne ?ducation et qui ?tait remplie de l'espoir de trouver le chemin qui l'emm?nerait vers la ?vie ?ternelle?.

(francuski) L'histoire de Belgrade au XIIe est document?e par diverses sources historiques qui, toutefois, relatent pour l'essentiel des ?v?nements li?s ? l'histoire de la ville ? cette ?poque. En ce sens, compte tenu de la position de la ville sur les rives de la Save et du Danube, c'est-?-dire pour l'?poque, sur la fronti?re nord de l'Empire byzantin face au royaume de Hongrie, les guerres opposant ces deux Etats constituent le th?me le plus fr?quemment des ?crivains m?di?vaux. S'agissant de la ville m?me les sources du XIIe si?cle ne nous en offrent aucune description pr?cise. Les auteurs grecs et latins se contentent le plus souvent de faire ?tat de quelques donn?es de base ? son sujet, ?voquant sa position g?ographiques et son aspect. L'auteur de ce travail communique une partie des r?sultats d'une analyse comparative des donn?es sur Belgrade au XIIe si?cle contenues dans les oeuvres des contemporains et t?moins visuels. Particuli?rement importantes sont ici les donn?es conserv?es dans l'oeuvre historique de Jean Kinnamos, qui a s?journ? ? Belgrade en 1165, puis les donn?es tir?es du texte du Pseudo-Ansbert sur la croisade de l'empereur allemand Fr?d?ric Ier Barberousse (1189), les donn?es des sources hongroises (Chronicon pictum Vindobonense), ainsi que les r?sultats des fouilles arch?ologiques effectu?es sur le site m?me de Belgrade. Jean Kinnamos d?signe toujours Belgrade comme une poliz et les sources latines comme une civitas. On rencontre aussi le terme arx d?signant une partie de l'agglom?ration ceinte de remparts. La ville fortifi?e de Belgrade s'est d?velopp?e au moyen ?ge sur l'aire de l'ancien camp militaire romain de Singidunum. Cet espace ?tait alors utilis? afin de r?pondre aux besoins militaires et administratifs de l'Empire byzantin. L'?poque des Comn?nes (1081-1185) voit ainsi la formation a Belgrade d'un important centre militaire et administratif sur une fronti?re menac?e. Le ch?teau de petites dimensions (136 *60 m) mis au jour lors de fouilles arch?ologiques syst?matiques dans la partie appel?e Ville Haute n'?tait qu'une partie de la ville fortifi?e. Avec le temps l'agglom?ration urbaine a d?bord? ? l'ext?rieur des remparts, mais lors des nombreuses guerres c'est elle qui a ?t? le plus expos?e aux destructions. Belgrade faisait partie des anciennes villes ?piscopales de l'?poque romaine et byzantine.

<span style="font-size: 11pt; color: black; font-family: 'Lucida Sans Unicode','sans-serif'"><p>P. Gounaridis</p><p>La date de la proclamation et du couronnement de Th&eacute;o&shy;dore I Laskaris<em>&nbsp;&nbsp;</em></p><p>L'&eacute;tude essaie d'&eacute;tablir la date de la proclamation et du couronnement du premier monarque de l'Etat de Nic&eacute;e Th&eacute;odore I Lascaris. La date de la proclamation pr&eacute;c&egrave;de d'une ann&eacute;e l'&eacute;loge que Nicetas Choniates a fait &agrave; Th&eacute;odore, quand ce dernier rentre d'une exp&eacute;dition. Cette exp&eacute;dition, dans l'&eacute;loge, est pr&eacute;sent&eacute;e comme une s&eacute;rie d'&eacute;v&eacute;nements sans interruption. En r&eacute;alit&eacute;, il s'agit de deux s&eacute;ries d'&eacute;v&eacute;nements s&eacute;par&eacute;es de quelques mois.</p><p>La premi&egrave;re s&eacute;rie est constitu&eacute;e des op&eacute;rations de Th&eacute;odore I contre David Comn&egrave;ne (occupation de Ploussias, si&egrave;ge d'Heracl&eacute;e) et l'inter&shy;vention des Latins de Constantinople en faveur de David. L'auteur d&eacute;montre que l'exp&eacute;dition des Latins en Asie Mineure pour divertir les forces de l'Etat de Nic&eacute;e du si&egrave;ge d'Heracl&eacute;e, n'est que l'exp&eacute;dition de l'empereur latin Henri d'Hainaut, rapport&eacute;e par Henri de Valenciennes. Cette exp&eacute;dition date du d&eacute;but de l'hiver de 1206/7.</p><p>La deuxi&egrave;me s&eacute;rie d'&eacute;v&eacute;nements se rapporte aux exp&eacute;ditions de Th&eacute;o&shy;dore contre les forces latines qui ont &eacute;t&eacute; install&eacute;es dans la r&eacute;gion de Nicom&eacute;die et finit par l'accord de tr&ecirc;ves entre le monarque de Nic&eacute;e et l'empereur latin en Mai/Juin 1207. L'auteur montre que: 1) la capture de Thierry de Los et de ses hommes, rapport&eacute;e par Villehardouin n'est que la victoire du g&eacute;n&eacute;ral de Th&eacute;odore I Andronic Gidos, victoire qui, dans l'&eacute;loge de Nicetas Choniates, est attribu&eacute;e au monarque de l'Etat nic&eacute;en. 2) L'expression de l'&eacute;loge &tau;ὸ&nu; &tau;&omicron;ῖ&chi;&omicron;&nu; ἐ&xi;&alpha;&lambda;&epsilon;ῖ&psi;&alpha;&iota; &kappa;&alpha;ὶ &tau;&omicron;ὺ&sigmaf; &tau;&omicron;ῦ&tau;&omicron;&nu; ἀ&lambda;&epsilon;ί&phi;&omicron;&nu;&tau;&alpha;&sigmaf; est bien l'exigence de Th&eacute;odore I que les Latins d&eacute;truisent les ouvrages de d&eacute;fense construits dans la r&eacute;gion de Nicom&eacute;die, pour conclure les tr&ecirc;ves de Mai/Juin 1207. Or, l'&eacute;loge a &eacute;t&eacute; &eacute;crite au retour de Th&eacute;odore de cette exp&eacute;dition, et par cons&eacute;quent sa proclamation avait eu lieu une ann&eacute;e auparavant.</p><p>La datation du couronnement de Th&eacute;odore d&eacute;pend de la date de l'&eacute;le&shy;ction du patriarche Michel IV Aut&ocirc;reianos &agrave; Nic&eacute;e. L'auteur reconsid&egrave;re les raisons qui ont men&eacute; A. Heisenberg &agrave; exclure l'an 1207 comme date de l'&eacute;lection du patriarche. Ces raisons ne sont point convaincantes. En effet, Heisenberg, d'une part, exclut 1207 consid&eacute;rant que Nicolas Mesarites, l'&acirc;me du synode, &eacute;tant &agrave; Constantinople le 17 Mars 1207, pour prononcer l'&eacute;loge fun&egrave;bre de son fr&egrave;re, ne pouvait pas participer au synode, qui devait s'ouvrir le lendemain. D'autre part, il souligne que la situation qui dominait dans la r&eacute;gion de Nicom&eacute;die n'aurait pas permis &agrave; Th&eacute;odore I de proc&eacute;der aux n&eacute;cessaires pour l'&eacute;lection du patriarche. Par cons&eacute;quent, selon Heisenberg, l'&eacute;lection du patriarche a eu lieu l'ann&eacute;e suivante. Pour autant, il y a toute une s&eacute;rie d'indices qui montrent que l'&eacute;loge fun&egrave;bre avait &eacute;t&eacute; prononc&eacute; &agrave; Nic&eacute;e, devant ceux qui allaient participer au synode pour l'&eacute;lection du patriarche. Par ailleurs, pendant les premiers mois de 1207, il y a eu de grandes p&eacute;riodes de paix et Th&eacute;odore I pouvait tr&egrave;s bien faire &eacute;lire le patriarche. L'auteur montre l'urgence de l'&eacute;glise byzantine d'avoir &agrave; sa t&ecirc;te un patriarche byzantin. Il essaie d'&eacute;tablir la date de la lettre du clerg&eacute; de Constantinople &agrave; Th&eacute;odore I, pour l'&eacute;lection du patriarche &agrave; Nic&eacute;e. La lettre mentionne l'hostilit&eacute; des Seljucides, qui a cess&eacute; par la conclusion d'un trait&eacute; de paix entre Th&eacute;odore I et les autorit&eacute;s du Sultanat d'Iconion. Ce trait&eacute;, qui pr&eacute;servait les fronti&egrave;res orientales de l'Etat de Nic&eacute;e, aurait &eacute;t&eacute; conclu avant que Th&eacute;odore I entreprenne ses op&eacute;rations contre les Latins &agrave; Nicom&eacute;die. Donc, cette lettre a &eacute;t&eacute; &eacute;crite au d&eacute;but du ca&shy;r&ecirc;me de 1207, ann&eacute;e de l'&eacute;lection du patriarche et du couronnement du basileus. Selon toute probabilit&eacute;, le patriarche Michel IV aurait &eacute;t&eacute; intronis&eacute; le 25 Mars, le jour de l'annonciation, et le basileus Th&eacute;odore aurait &eacute;t&eacute; couronn&eacute; le 18 avril, le jour des P&acirc;ques.</p></span><span style="font-size: 11pt; color: black; font-family: 'Lucida Sans Unicode','sans-serif'">d&rsquo;Heracl&eacute;e) et l&rsquo;inter&shy;vention des Latins de </span><span style="font-size: 11pt; color: black; font-family: 'Lucida Sans Unicode','sans-serif'">Constantinople </span><span style="font-size: 11pt; color: black; font-family: 'Lucida Sans Unicode','sans-serif'">en faveur de David. L&rsquo;auteur d&eacute;montre que l&rsquo;exp&eacute;dition des Latins en Asie Mineure pour divertir les forces de l&rsquo;Etat de Nic&eacute;e du si&egrave;ge d&rsquo;Heracl&eacute;e, n&rsquo;est que l&rsquo;exp&eacute;dition de l&rsquo;empereur latin Henri d&rsquo;Hainaut, rapport&eacute;e par Henri de </span><span style="font-size: 11pt; color: black; font-family: 'Lucida Sans Unicode','sans-serif'">Valenciennes. </span><span style="font-size: 11pt; color: black; font-family: 'Lucida Sans Unicode','sans-serif'">Cette exp&eacute;dition date du d&eacute;but de l&rsquo;hiver de </span><span style="font-size: 11pt; color: black; font-family: 'Lucida Sans Unicode','sans-serif'">1206/7.</span><span style="font-size: 11pt; color: black; font-family: 'Lucida Sans Unicode','sans-serif'">La deuxi&egrave;me s&eacute;rie d&rsquo;&eacute;v&eacute;nements se rapporte aux exp&eacute;ditions de Th&eacute;o&shy;dore contre les forces latines qui ont &eacute;t&eacute; install&eacute;es dans la r&eacute;gion de Nicom&eacute;die et finit par l&rsquo;accord de tr&ecirc;ves entre le monarque de Nic&eacute;e et l&rsquo;empereur latin en Mai/Juin </span><span style="font-size: 11pt; color: black; font-family: 'Lucida Sans Unicode','sans-serif'">1207. </span><span style="font-size: 11pt; color: black; font-family: 'Lucida Sans Unicode','sans-serif'">L&rsquo;auteur montre que: </span><span style="font-size: 11pt; color: black; font-family: 'Lucida Sans Unicode','sans-serif'">1) </span><span style="font-size: 11pt; color: black; font-family: 'Lucida Sans Unicode','sans-serif'">la capture de Thierry de Los et de ses hommes, rapport&eacute;e par Villehardouin n&rsquo;est que la victoire du g&eacute;n&eacute;ral de Th&eacute;odore </span><span style="font-size: 11pt; color: black; font-family: 'Lucida Sans Unicode','sans-serif'">I </span><span style="font-size: 11pt; color: black; font-family: 'Lucida Sans Unicode','sans-serif'">Andronic Gidos, victoire qui, dans l&rsquo;&eacute;loge de Nicetas Choniates, est attribu&eacute;e au monarque de l&rsquo;Etat nic&eacute;en. </span><span style="font-size: 11pt; color: black; font-family: 'Lucida Sans Unicode','sans-serif'">2) </span><span style="font-size: 11pt; color: black; font-family: 'Lucida Sans Unicode','sans-serif'">L&rsquo;expression de l&rsquo;&eacute;loge </span><span style="font-size: 11pt; color: black; font-family: 'Palatino Linotype','serif'">&tau;ὸ&nu;</span><span style="font-size: 11pt; color: black; font-family: 'Palatino Linotype','serif'"> </span><span style="font-size: 11pt; color: black; font-family: 'Palatino Linotype','serif'">&tau;&omicron;ῖ&chi;&omicron;&nu;</span><span style="font-size: 11pt; color: black; font-family: 'Palatino Linotype','serif'"> </span><span style="font-size: 11pt; color: black; font-family: 'Palatino Linotype','serif'">ἐ&xi;&alpha;&lambda;&epsilon;ῖ&psi;&alpha;&iota;</span><span style="font-size: 11pt; color: black; font-family: 'Palatino Linotype','serif'"> </span><span style="font-size: 11pt; color: black; font-family: 'Palatino Linotype','serif'">&kappa;&alpha;ὶ</span><span style="font-size: 11pt; color: black; font-family: 'Palatino Linotype','serif'"> </span><span style="font-size: 11pt; color: black; font-family: 'Palatino Linotype','serif'">&tau;&omicron;ὺ&sigmaf;</span><span style="font-size: 11pt; color: black; font-family: 'Palatino Linotype','serif'"> </span><span style="font-size: 11pt; color: black; font-family: 'Palatino Linotype','serif'">&tau;&omicron;ῦ&tau;&omicron;&nu;</span><span style="font-size: 11pt; color: black; font-family: 'Palatino Linotype','serif'"> </span><span style="font-size: 11pt; color: black; font-family: 'Palatino Linotype','serif'">ἀ&lambda;&epsilon;ί&phi;&omicron;&nu;&tau;&alpha;&sigmaf;</span><span style="font-size: 11pt; color: black; font-family: 'Palatino Linotype','serif'"> </span><span style="font-size: 11pt; color: black; font-family: 'Lucida Sans Unicode','sans-serif'">est bien l&rsquo;exigence de Th&eacute;odore </span><span style="font-size: 11pt; color: black; font-family: 'Lucida Sans Unicode','sans-serif'">I </span><span style="font-size: 11pt; color: black; font-family: 'Lucida Sans Unicode','sans-serif'">que les Latins d&eacute;truisent les ouvrages de d&eacute;fense construits dans la r&eacute;gion de Nicom&eacute;die, pour conclure les tr&ecirc;ves de Mai/Juin </span><span style="font-size: 11pt; color: black; font-family: 'Lucida Sans Unicode','sans-serif'">1207. </span><span style="font-size: 11pt; color: black; font-family: 'Lucida Sans Unicode','sans-serif'">Or, l&rsquo;&eacute;loge a &eacute;t&eacute; &eacute;crite au retour de Th&eacute;odore de cette exp&eacute;dition, et par cons&eacute;quent sa proclamation avait eu lieu une ann&eacute;e auparavant.</span><span style="font-size: 11pt; color: black; font-family: 'Lucida Sans Unicode','sans-serif'">La datation du couronnement de Th&eacute;odore d&eacute;pend de la date de l&rsquo;&eacute;le&shy;ction du patriarche Michel </span><span style="font-size: 11pt; color: black; font-family: 'Lucida Sans Unicode','sans-serif'">IV </span><span style="font-size: 11pt; color: black; font-family: 'Lucida Sans Unicode','sans-serif'">Aut&ocirc;reianos &agrave; Nic&eacute;e. L&rsquo;auteur reconsid&egrave;re les raisons qui ont men&eacute; A. </span><span style="font-size: 11pt; color: black; font-family: 'Lucida Sans Unicode','sans-serif'">Heisenberg </span><span style="font-size: 11pt; color: black; font-family: 'Lucida Sans Unicode','sans-serif'">&agrave; exclure l&rsquo;an </span><span style="font-size: 11pt; color: black; font-family: 'Lucida Sans Unicode','sans-serif'">1207 </span><span style="font-size: 11pt; color: black; font-family: 'Lucida Sans Unicode','sans-serif'">comme date de l&rsquo;&eacute;lection du patriarche. Ces raisons ne sont point convaincantes. En effet, </span><span style="font-size: 11pt; color: black; font-family: 'Lucida Sans Unicode','sans-serif'">Heisenberg, </span><span style="font-size: 11pt; color: black; font-family: 'Lucida Sans Unicode','sans-serif'">d&rsquo;une part, exclut </span><span style="font-size: 11pt; color: black; font-family: 'Lucida Sans Unicode','sans-serif'">1207 </span><span style="font-size: 11pt; color: black; font-family: 'Lucida Sans Unicode','sans-serif'">consid&eacute;rant que Nicolas Mesarites, l&rsquo;&acirc;me du synode, &eacute;tant &agrave; </span><span style="font-size: 11pt; color: black; font-family: 'Lucida Sans Unicode','sans-serif'">Constantinople </span><span style="font-size: 11pt; color: black; font-family: 'Lucida Sans Unicode','sans-serif'">le </span><span style="font-size: 11pt; color: black; font-family: 'Lucida Sans Unicode','sans-serif'">17 </span><span style="font-size: 11pt; color: black; font-family: 'Lucida Sans Unicode','sans-serif'">Mars </span><span style="font-size: 11pt; color: black; font-family: 'Lucida Sans Unicode','sans-serif'">1207, </span><span style="font-size: 11pt; color: black; font-family: 'Lucida Sans Unicode','sans-serif'">pour prononcer l&rsquo;&eacute;loge fun&egrave;bre de son fr&egrave;re, ne pouvait pas participer au synode, qui devait s&rsquo;ouvrir le lendemain. D&rsquo;autre part, il souligne que la situation qui dominait dans la r&eacute;gion de Nicom&eacute;die n&rsquo;aurait pas permis &agrave; Th&eacute;odore </span><span style="font-size: 11pt; color: black; font-family: 'Lucida Sans Unicode','sans-serif'">I </span><span style="font-size: 11pt; color: black; font-family: 'Lucida Sans Unicode','sans-serif'">de proc&eacute;der aux n&eacute;cessaires pour l&rsquo;&eacute;lection du patriarche. Par cons&eacute;quent, selon </span><span style="font-size: 11pt; color: black; font-family: 'Lucida Sans Unicode','sans-serif'">Heisenberg, </span><span style="font-size: 11pt; color: black; font-family: 'Lucida Sans Unicode','sans-serif'">l&rsquo;&eacute;lection du patriarche a eu lieu l&rsquo;ann&eacute;e suivante. Pour autant, il y a toute une s&eacute;rie d&rsquo;indices qui montrent que l&rsquo;&eacute;loge fun&egrave;bre avait &eacute;t&eacute; prononc&eacute; &agrave; Nic&eacute;e, devant ceux qui allaient participer au synode pour l&rsquo;&eacute;lection du patriarche. Par ailleurs, pendant les premiers mois de </span><span style="font-size: 11pt; color: black; font-family: 'Lucida Sans Unicode','sans-serif'">1207, </span><span style="font-size: 11pt; color: black; font-family: 'Lucida Sans Unicode','sans-serif'">il y a eu de grandes p&eacute;riodes de paix et Th&eacute;odore </span><span style="font-size: 11pt; color: black; font-family: 'Lucida Sans Unicode','sans-serif'">I </span><span style="font-size: 11pt; color: black; font-family: 'Lucida Sans Unicode','sans-serif'">pouvait tr&egrave;s bien faire &eacute;lire le patriarche. L&rsquo;auteur montre l&rsquo;urgence de l&rsquo;&eacute;glise byzantine d&rsquo;avoir &agrave; sa t&ecirc;te un patriarche byzantin. Il essaie d&rsquo;&eacute;tablir la date de la lettre du clerg&eacute; de </span><span style="font-size: 11pt; color: black; font-family: 'Lucida Sans Unicode','sans-serif'">Constantinople </span><span style="font-size: 11pt; color: black; font-family: 'Lucida Sans Unicode','sans-serif'">&agrave; Th&eacute;odore </span><span style="font-size: 11pt; color: black; font-family: 'Lucida Sans Unicode','sans-serif'">I, </span><span style="font-size: 11pt; color: black; font-family: 'Lucida Sans Unicode','sans-serif'">pour l&rsquo;&eacute;lection du patriarche &agrave; Nic&eacute;e. La lettre mentionne l&rsquo;hostilit&eacute; des Seljucides, qui a cess&eacute; par la conclusion d&rsquo;un trait&eacute; de paix entre Th&eacute;odore </span><span style="font-size: 11pt; color: black; font-family: 'Lucida Sans Unicode','sans-serif'">I </span><span style="font-size: 11pt; color: black; font-family: 'Lucida Sans Unicode','sans-serif'">et les autorit&eacute;s du Sultanat d&rsquo;Iconion. Ce trait&eacute;, qui pr&eacute;servait les fronti&egrave;res orientales de l&rsquo;Etat de Nic&eacute;e, aurait &eacute;t&eacute; conclu avant que Th&eacute;odore </span><span style="font-size: 11pt; color: black; font-family: 'Lucida Sans Unicode','sans-serif'">I </span><span style="font-size: 11pt; color: black; font-family: 'Lucida Sans Unicode','sans-serif'">entreprenne ses op&eacute;rations contre les Latins &agrave; Nicom&eacute;die. Donc, cette lettre a &eacute;t&eacute; &eacute;crite au d&eacute;but du ca&shy;r&ecirc;me de </span><span style="font-size: 11pt; color: black; font-family: 'Lucida Sans Unicode','sans-serif'">1207, </span><span style="font-size: 11pt; color: black; font-family: 'Lucida Sans Unicode','sans-serif'">ann&eacute;e de l&rsquo;&eacute;lection du patriarche et du couronnement du </span><span style="font-size: 11pt; color: black; font-family: 'Lucida Sans Unicode','sans-serif'">basileus. </span><span style="font-size: 11pt; color: black; font-family: 'Lucida Sans Unicode','sans-serif'">Selon toute probabilit&eacute;, le patriarche Michel </span><span style="font-size: 11pt; color: black; font-family: 'Lucida Sans Unicode','sans-serif'">IV </span><span style="font-size: 11pt; color: black; font-family: 'Lucida Sans Unicode','sans-serif'">aurait &eacute;t&eacute; intronis&eacute; le </span><span style="font-size: 11pt; color: black; font-family: 'Lucida Sans Unicode','sans-serif'">25 </span><span style="font-size: 11pt; color: black; font-family: 'Lucida Sans Unicode','sans-serif'">Mars, le jour de l&rsquo;annonciation, et le </span><span style="font-size: 11pt; color: black; font-family: 'Lucida Sans Unicode','sans-serif'">basileus </span><span style="font-size: 11pt; color: black; font-family: 'Lucida Sans Unicode','sans-serif'">Th&eacute;odore aurait &eacute;t&eacute; couronn&eacute; le </span><span style="font-size: 11pt; color: black; font-family: 'Lucida Sans Unicode','sans-serif'">18 </span><span style="font-size: 11pt; color: black; font-family: 'Lucida Sans Unicode','sans-serif'">avril, le jour des P&acirc;ques.</span>

AbstractIon implantation into silica followed by thermal annealing is an established growth method for Si and Ge nanocrystals. We demonstrate that growth of Group IV semiconductor nanocrystals can be suppressed by co-implantation of oxygen prior to annealing. For Si nanocrystals, at low Si/O dose ratios, oxygen co-implantation leads to a reduction of the average nanocrystal size and a blue-shift of the photoluminescence emission energy. For both Si and Ge nanocrystals, at larger Si/O or Ge/O dose ratios, the implanted specie is oxidized and nanocrystals do not form. This chemical deactivation was utilized to achieve patterned growth of Si and Ge nanocrystals. Si was implanted into a thin SiO2 film on a Si substrate followed by oxygen implantation through an electron beam lithographically defined stencil mask. Thermal annealing of the co-implanted structure yields two-dimensionally patterned growth of Si nanocrystals under the masked regions. We applied a previously developed process to obtain exposed nanocrystals by selective HF etching of the silica matrix to these patterned structures. Atomic force microscopy (AFM) of etched structures revealed that exposed nanocrystals are not laterally displaced from their original positions during the etching process. Therefore, this process provides a means of achieving patterned structures of exposed nanocrystals. The possibilities for scaling this chemical-based lithography process to smaller features and for extending it to 3-D patterning is discussed.

ABSTRACTRapid thermal processing chemical vapor deposition was used to grow single and multilaye repitaxial GexSil-x/Si structures on (100)Si substrates using GeH4 and SiH2Cl2 at 900°C and 1000°C with SiH2Cl2:GeH4 ratios of 14:1 to 95:1 at 5 Torr. Misfit dislocation free layers with few threading dislocations were grown for Ge concentrations of up to 13%. Misfit dislocation networks aligned along <110> were formed at the interface of films with higher Ge concentrations. Dislocation loops were also found at the interface. GexSil-x layers grown at 1000°C were highly crystalline, but relaxed. In multi-layer structures, AES depth profiles showed Ge pile-up at the GexSi1-x/Si interface of layers with higher Ge concentrations.

ABSTRACTWe study the interface between un-alloyed a-Si:H,F and an a-Si0.4,Ge0.6:H,F alloy using superlattice structures. From infrared spectroscopy we estimate a width of 8 A for the excess hydrogen layer, and X-ray diffraction data give us a width of 2Å contributing to the width of the diffraction peak. Vibrational Raman scattering data show that the ratios of the number of Si-Si, Ge-Ge and Si-Ge bonds is not altered by changing the number of interfaces. This fact allows us to establish an upper limit for the interface width of 3 atomic layers, i.e. one layer in each partner plus an intermediate layer.

ABSTRACTWe report the recent progress of crystallization of amorphous silicon (a-Si), amorphous germanium (a-Ge) and amorphous silicon germanium alloy (a-SiGe) using a pulsed-Xenon-lamp system with multiple lamps. The precursor materials were deposited using a sputtering machine on display glass substrates maintained on a rotary holder. The RF powers on the silicon and germanium targets were varied to control the Ge/Si ratio in the materials. The film thickness was in the range of 50-100 nm, targeting the application in thin film transistors (TFT). The samples were pre-heated to 350-450°C in a conveyer chamber with nitrogen flow before the crystallization. The materials were characterized using AFM, Raman and Spectroscopic Ellipsometry. We demonstrated that we can uniformly crystallize a-Si, a-SiGe, and a-Ge with a single-pulse or multiple-pulse process on 10×5 cm2 glass substrates. We found that the required crystallization power for a-Ge is much lower than for a-Si. The power needed to crystallize a-SiGe is between the power required for a-Ge and a-Si crystallizations, and it increased with increasing Si fraction. No Raman signal was measurable in the as-deposited films. Strong Raman peaks at 520 cm-1 and 290 cm-1 were observed in the pulsed-lamp crystallized poly-Si and poly-Ge films, respectively. Distinct Ge-Ge, Si-Ge, and Si-Si vibration modes were observed at ~285 cm-1, ~390 cm-1, and ~470 cm-1, respectively, in the poly-SiGe films formed after the pulsed-light treatments. Their intensity ratios and the peak positions depended on the Ge/Si ratio and the light intensity used for the crystallization. AFM images showed the formation of large grains with increased surface roughness.

AbstractThe evolution of interfaces of short-period (SimGen)p superlattices upon annealing has been studied by x-ray reflectometry and Raman scattering spectroscopy. Isothermal annealing treatments at 700° C resulted in a significant material redistribution as evidenced by a strong decay of the superlattice x-ray satellites and by the decay of longitudinal acoustic modes and changes in the optical mode intensity ratios in Raman scattering. Interdiffusion was more pronounced in superlattices of short periodicity. This may possibly be explained by the strong composition dependence of the diffusivity of Ge atoms in Sil-xGex alloys and the degree of preexisting interfacial mixing. This composition dependence of the diffusion may favor atomic displacement parallel to the interfaces leading to an initial smoothing of the interfaces

New functional foods and beverages can be developed using bioactive compounds present in pequi oil. Complex coacervation is an encapsulation method used for preserving bioactive molecules, especially those that are hydrophobic or sensitive to high temperatures. The objective of this work was to produce and characterize pequi oil microparticles using cashew gum/gelatin matrix (CG/GE) through complex coacervation. Gum Arabic (GA) was also studied in comparison with CG. The coacervation process was performed withoutpequi oil to determine the ideal proportions of the matrix components, followed by the embedding of the oil inthe microparticles for evaluation. Satisfactory microparticles were produced at pH 4.5 in the weight ratios of CG/GE = 2:1 and GA/GE = 1:3. Pequi oil release was greater in acidic pH, especially at pH 2 for the CG/GE matrix. The encapsulation efficiency for CG/GE and GA/GE was 72.53% (±4.80) and 82.77% (±6.09), respectively. The results showed that the CG/GE combination seemed very promising as anencapsulation matrix, especially for food applications involving pH values higher than 3.