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CoSm permanent magnets are characterized by high coercivity, which is due to the formation of a cellular nanostructure. For the understanding and optimization of these magnets, the evolution and morphology of the cellular structure need to be analyzed, most commonly by transmission electron microscopy (TEM). Meanwhile, high-resolution scanning electron microscopy (SEM) is enabling the visualization and large-scale imaging of the nanostructure while requiring relatively little preparation effort, combined with easy sample handling. Different preparation techniques will be used to visualize different microstructural constituents, enabling the analysis of their morphologies and fractions.

The electrochemical performance of mechanically spheroidized natural and synthetic graphite particles is significantly influenced by the type of spheroidization process used and the applied conditions. In order to guarantee a consistent and high material quality, spherical graphite particles have to be carefully benchmarked before use. Three spherical natural graphites and three spheroidized synthetic graphites are characterized using several physical analysis methods. A special focus is laid on the internal morphology and texture, which has been studied by scanning electron microscopy (SEM) – focused ion beam (FIB) cross-sections and tomography. For the spheroidized natural graphites under investigation this method indicates a volume of closed pores in the range of 4–5% and of open pores of 0.5% or less of the total particle volume. With increasing energy impact during the spheroidization process the open porosity increases and the closed porosity decreases.

A series of Li2 MnSiO4 samples with various Li, Mn, and/or Si concentrations are reported to study for the first time the effect of impurities and deviation from ideal stoichiometry on electrochemical behavior. Carbon-coated and nanosized powders are obtained at 600 °C and compared with those synthetized at 900 °C. Samples are investigated using XRD, SEM, high-resolution TEM, attenuated total reflection infrared spectroscopy and Brunauer-Emmett-Teller surface area to characterize crystal structure, particle size, impurity amount, morphology, and surface area. Electrochemical performance depends on impurities such as MnO as well as crystallite size, surface area, and non-stoichiometric phases, which lead to the formation of additional polymorphs such as Pmnb and P21 /n of Li2 MnSiO4 at low calcination temperatures. A systematic analysis of the main parameters affecting the electrochemical behavior is performed and trends in synthesis are identified. The findings can be applied to optimize different synthesis routes for attaining stoichiometric and phase-pure Pmn21 Li2 MnSiO4 as cathode material for Li-ion batteries.

We have developed a highly active nanostructured iridium catalyst for anodes of proton exchange membrane (PEM) electrolysis. Clusters of nanosized crystallites are obtained by reducing surfactant-stabilized IrCl3 in water-free conditions. The catalyst shows a five-fold higher activity towards oxygen evolution reaction (OER) than commercial Ir-black. The improved kinetics of the catalyst are reflected in the high performance of the PEM electrolyzer (1 mg(Ir) cm(-2)), showing an unparalleled low overpotential and negligible degradation. Our results demonstrate that this enhancement cannot be only attributed to increased surface area, but rather to the ligand effect and low coordinate sites resulting in a high turnover frequency (TOF). The catalyst developed herein sets a benchmark and a strategy for the development of ultra-low loading catalyst layers for PEM electrolysis.

The application of detector strategies in scanning electron microscopy (SEM) correlated with computer tomography (CT) and light microscopy (LM) delivered unique new insights in degeneration effects of lithium-ion batteries. There we exemplary studied reference, cycled and storage cells. High-resolution SEM permit to visualize a coating on top of the cathode material of the treated cells for the first time, which also connects the conductive additives and battery active material. This confirms the assumption of a solid permeable interface on top of the cathode. The detection of low-loss reflected backscattered electrons for energies beyond 3 keV increases the available spatial resolution for material contrast. This offered the opportunity to address the atomic number of precipitates in the nm range inside the coating to be above carbon and below Li1-x(Ni1/3Mn1/3Co1/3)O2 (NMC). Applying voltage contrast enables to show the difference in electronic conductivity of plate-like features on top of the cycled cell anode, most likely lithium plating. Cross sectional images of the anode delivered a significant change of the surficial-area morphology for the treated cells with increasing porosity. Precipitates were detected on top of the separator foil. An increment in thickness of the entire treated cells by computer tomography was found, which can be explained by the alteration of the anode, separator and cathode.

Journal of Petrology, 52 (4), ISSN:0022-3530, ISSN:1460-2415

It is demonstrated that energy-filtered transmission electron microscope enables following of in situ changes of the Ca-L2,3 edge which can originate from variations in both local symmetry and bond lengths. Low accelerating voltages of 20 and 40 kV slow down radiation damage effects and enable study of the start and finish of phase transformations. We observed electron beam-induced phase transformation of single crystalline calcite (CaCO3) to polycrystalline calcium oxide (CaO) which occurs in different stages. The coordination of Ca in calcite is close to an octahedral one streched along the direction. Changes during phase transformation to an octahedral coordination of Ca in CaO go along with a bond length increase by 5 pm, where oxygen is preserved as a binding partner. Electron loss near-edge structure of the Ca-L2,3 edge show four separated peaks, which all shift toward lower energies during phase transformation at the same time the energy level splitting increases. We suggest that these changes can be mainly addressed to the change of the bond length on the order of picometers. An important pre-condition for such studies is stability of the energy drift in the range of meV over at least 1 h, which is achieved with the sub-Ångström low-voltage transmission electron microscope I prototype microscope.

In this study, time-of-flight secondary ion mass spectrometry (ToF-SIMS) and advanced electron microscopy (scanning electron microscopy (SEM), scanning transmission electron microscopy (STEM) and transmission electron microscopy (TEM)) were applied to detect and analyse different nano-scaled protein coatings on gold nanoparticles (NP). The NP were coated with collagen type I and fibronectin as well as different combinations of these proteins. These two main proteins in human cell organization and tissue formation were identified with the aid of ToF-SIMS by typical amino acid mass peak detection. In addition, the protein-coated particles were investigated by TEM and SEM to get information about the protein structure, the protein layer thickness on the particle surfaces and the reaction of NP in different protein solutions. In this study, a differentiation of diverse protein induced particle agglomeration was proven. The investigations of this study were part of the Specific Targeted Research Project CellNanoTox (project no. NMP4-CT-2006-032731) funded by the European Commission under the 6th EU Framework Programme for Research and Technological Development. Copyright © 2013 John Wiley & Sons, Ltd.

The toxicological effects of cobalt nanoparticles (Co-NPs) aggregates were examined and compared with those of cobalt ions (Co-ions) using six different cell lines representing lung, liver, kidney, intestine, and the immune system. Dose-response curves were studied in the concentration range of 0.05-1.0 mM, employing 3-(4,5-dimethylthiazol-2-Yl)-2,5-diphenyltetrazolium bromide test, neutral red, and Alamar blue as end point assays following exposures for 48 and 72 h. Data analysis and predictive modeling of the obtained data sets were executed by employing a decision tree model (J48), where training and validation were carried out by an iterative process. It was established, as expected, that concentration is the highest rank parameter. This is because concentration parameter provides the highest information gain with respect to toxicity. The second-rank parameter emerged to be either the compound type (Co-ions or Co-NPs) or the cell model, depending on the concentration range. The third and the lowest rank in the model was exposure duration. The hierarchy of cell sensitivity toward cobalt ions was found to obey the following sequence of cell lines: A549 > MDCK > NCIH441 > Caco-2 > HepG2 > dendritic cells (DCs), with A549 being the most sensitive cell line and primary DCs were the least sensitive ones. However, a different hierarchy pattern emerged for Co-NPs: A549 = MDCK = NCIH441 = Caco-2 > DCs > HepG2. The overall findings are in line with the hypothesis that the toxic effects of aggregated cobalt NPs are mainly due to cobalt ion dissolution from the aggregated NPs.

Microtextural changes brought about by heating alkali feldspar crystals from the Shap granite, northern England, at atmospheric pressure, have been studied using transmission and scanning electron microscopy. A typical unheated phenocryst from Shap is composed of about 70 vol% of tweed orthoclase with strain-controlled coherent or semicoherent micro- and crypto-perthitic albite lamellae, with maximum lamellar thicknesses 700°C, and after >48 h at 700°C, all such regions were essentially compositionally homogeneous, as indicated by X-ray analyses at fine scale in the transmission electron microscope. Changes in lamellar thickness with time at different T point to an activation energy of ~350 kJmol−1. A lamella which homogenised after 6,800 h at 600°C, therefore, would have required only 0.6 s to do so in the melting interval at 1,100°C. Subgrains in patch perthite homogenised more slowly than coherent lamellae and chemical gradients in patches persisted for >5,000 h at 700°C. Homogenisation T is in agreement with experimentally determined solvi for coherent ordered intergrowths, when a 50–100°C increase in T for An1 is applied. Homogenisation of lamellae appears to proceed in an unexpected manner: two smooth interfaces, microstructurally sharp, advance from the original interfaces toward the mid-line of each twinned, semicoherent lamella. In places, the homogenisation interfaces have shapes reflecting the local arrangements of nanotunnels or pull-aparts. Analyses confirm that the change in alkali composition is also relatively sharp at these interfaces. Si–Al disordering is far slower than alkali homogenisation so that tweed texture in orthoclase, tartan twinning in irregular microcline, and Albite twins in albite lamellae and patches persisted in all our experiments, including 5,478 h at 700°C, 148 h at 1,000°C and 5 h at 1,100°C, even though the ensemble in each case was chemically homogeneous. Nanotunnels and pull-aparts were modified after only 50 min at 500°C following the simulated 40Ar/39Ar step-heating schedule. New features called ‘slots’ developed away from albite lamellae, often with planar traces linking slots to the closest lamella. Slot arrays were often aligned along ghost-like regions of diffraction contrast which may mark the original edges of lamellae. We suggest that the slot arrays result from healing of pull-aparts containing fluid. At 700°C and above, the dominant defects were subspherical ‘bubbles’, which evolved from slots or from regions of deuteric coarsening. The small degree of partial melting observed after 5 h at 1,100°C was often in the vicinity of bubbles. Larger micropores, which formed at subgrain boundaries in patch perthite during deuteric coarsening, retain their shape up to the melting point, as do the subgrain boundaries themselves. It is clear that modification of defects providing potential fast pathways for diffusion in granitic alkali feldspars begins below 500°C and that defect character progressively changes up to, and beyond, the onset of melting.

The pseudomorphic replacement of chlorapatite by hydroxy-fluor-apatite is associated with metasomatism of the Odegarden metagabbro (Bamble, south Norway). Primary fluor-chlorapatite in the protolith gabbro is non-porous and homogenous in composition with F-content of up to 3.5 wt% and Cl-content up to 2 wt.%. Metasomatism transforms apatite during multi-stage replacement reactions: I) Magmatic apatite was transformed to chlorapatite with Cl-content of up to 6.8 wt.% during scapolitisation. II) A secondary pseudomorphic replacement reaction which transforms chlorapatite to porous hydroxy-fluor-apatite with only minor Cl is related to albitisation. Laser ablation inductively coupled mass spectrometry (LA ICPMS) data from the primary fluor-chlorapatite shows in general a high content of Sr, Y, REE and Th. Chlor- and hydroxy-fluor-apatite show depletion in Co, Ni, Sr, Cd, Pb, Th and U, and enrichment in V and Ba, relative to the primary apatite. The replacement interface of chlorapatite to hydroxy-fluor-apatite is studied by energy-filtered transmission electron microscopy (TEM). The interface is sharp on a nano-scale, and the crystallographic orientation of the apatite is preserved. These observations, together with the porosity development in the hydroxy-fluor-apatite suggest that the replacement mechanism is by interface-coupled dissolution-reprecipitation.

The mechanism of re-equilibration of albite in a hydrothermal fluid has been investigated experimentally using natural albite crystals in an aqueous KCl solution enriched in 18O at 600°C and 2 kbars pressure. The reaction is pseudomorphic and produces a rim of K-feldspar with a sharp interface on a nanoscale which moves into the parent albite with increasing reaction time. Transmission electron microscopy (TEM) diffraction contrast and X-ray powder diffraction (XRD) show that the K-feldspar has a very high defect concentration and a disordered Al, Si distribution, compared to the parent albite. Raman spectroscopy shows a frequency shift of the Si-O-Si bending vibration from ~476 cm−1 in K-feldspar formed in normal 16O aqueous solution to ~457 cm−1 in the K-feldspar formed in 18O-enriched solution, reflecting a mass-related frequency shift due to a high enrichment of 18O in the K-feldspar silicate framework. Raman mapping of the spatial distribution of the frequency shift, and hence 18O content, compared with major element distribution maps, show a 1:1 correspondence between the reaction rim formed by the replacement of albite by K-feldspar, and the oxygen isotope re-equilibration. The textural and chemical characteristics as well as the kinetics of the replacement of albite by K-feldspar are consistent with an interface-coupled dissolution-reprecipitation mechanism.

PEM water electrolysis has recently emerged as one of the most promising technologies for large H2 production from a temporal surplus of renewable electricity; yet it is expensive, partly due to the use of large amounts of Ir present in the anode. Here we report the development and characterization of a cost-effective catalyst, which consists of metallic Ir nanoparticles supported on commercial Ti4O7. The catalyst is synthesized by reducing IrCl3 with NaBH4 in a suspension containing Ti4O7, cetyltrimethylammonium bromide (CTAB) and anhydrous ethanol. No thermal treatment was applied afterwards in order to preserve the high conductivity of Ti4O7 and the metallic properties of Ir. Electron microscopy images show an uniform distribution of mostly single Ir particles covering the electro-ceramic support, although some agglomerates are still present. X-ray diffraction (XRD) analysis reveals a cubic face centered structure of Ir nanoparticles with a crystallite size of ca. 1.8 nm. According to X-ray photoelectron spectroscopy (XPS), the ratio of metallic Ir and Ir-oxide, identified as Ir(3+), is 3 : 1 after the removal of surface contamination. Other surface properties such as primary particle size distribution and surface potential were determined by atomic force microscopy (AFM). Cyclic and linear voltammetric measurements were conducted to study the electrochemical surface and kinetics of Ir-black and Ir/Ti4O7. The developed catalyst outperforms the commercial Ir-black in terms of mass activity for the oxygen evolution reaction (OER) in acid medium by a factor of four, measured at 0.25 V overpotential and room temperature. In general, the Ir/Ti4O7 catalyst exhibits improved kinetics and higher turnover frequency (TOF) compared to Ir-black. The developed Ir/Ti4O7 catalyst allows reducing the precious metal loading in the anode of a PEM electrolyzer by taking advantage of the use of an electro-ceramic support.

Transmission electron microscopy shows that red-clouded alkali feldspars from granitic rocks contain numerous open pores up to several hundred nanometres in cross-section, and that almost every pore contains rosettes or needles of crystalline hematite. In the samples described here, the hematite forms at the reaction interfaces at which plagioclase feldspar is replaced by alkali feldspar. These observations, together with the fact that the origin of the porosity can be explained by the mechanism of sub-solidus mineral–fluid replacement processes, indicate that hematite is a direct product of fluid–rock interaction and is not a solid state exsolution product from the feldspar.

Lithium-sulphur batteries have generated tremendous research interest due to their high theoretical energy density and potential cost-effectiveness. The commercial realization of Li-S batteries is still hampered by reduced cycle life associated with the formation of electrolyte soluble higher-order polysulphide (Li2Sx, x = 4–8) intermediates, leading to capacity fading, self-discharge and a multistep voltage profile. Herein, we have realized a practical approach towards a direct transformation of sulphur to Li2S2/Li2S in lithium-sulphur batteries by alteration of the reaction pathway. A coconut shell derived ultramicroporous carbon-sulphur composite cathode has been used as reaction directing template for the sulphur. The lithiation/delithiation and capacity fading mechanism of microporous carbon confined sulphur composite was revealed by analyzing the subsurface using X-ray photoelectron spectroscopy. No higher-order polysulphides were detected in the electrolyte, on the surface and in the subsurface of the cathode composite. The altered reaction pathway is reflected by a single-step profile in the discharge/charge of a lithium-sulphur cell.

The oxidation state of iron oxide nanoparticles was determined using the two principally different technical realisations of energy filtering TEM, in one case using the JEOL 3010 equipped with a LaB6 cathode and a post-column GIF and in the second, the newly designed LIBRA 200FE equipped with an corrected in-column 90 degrees energy filter and a field emission gun (Schottky emitter). The samples studied were oxide-coated iron nanoparticles, and iron oxide inclusions in feldspars in granites. Five possible candidates exist for the iron-oxide phases: FeO, alpha-Fe2O3 (hematite), gamma-Fe2O3 (maghemite), Fe3O4 (magnetite) or alpha-FeO(OH) (goethite). Fingerprinting the O K-edge ELNES allows to distinguish between oxide phases with the same stochiometry and enables to make a first selection of possible candidates. The additional determination of the chemical composition allows unique identification of the phase present. For the oxide coated iron nanoparticles the most probable iron oxide phase of the shell is maghemite, which was additionally confirmed by HRTEM studies. The second studied system were iron oxide needles in alkali feldspar, where we obtained hematite as the most probable phase. There we additionally demonstrated the drastic changes of the ELNES of the O K-edge for the alkali feldspar and iron oxide needle by spatially resolved EELS.

The magnetic susceptibility and Curie temperatures T c have been investigated for a series of synthetic samples with solid-solution compositions ranging from pure magnetite (Fe3O4) to hercynite (FeAl2O4). The determined T c can be fitted by a straight line, which also fits the theoretical values for these end-members. With increasing hercynite concentration, susceptibility curves for one heating and cooling cycle become irreversible, indicating changes in the structural state of the samples during annealing. These changes occur in specific temperature ranges for each composition. For a sample of composition Mag40Hec60, irreversible changes occurring between about 200 and 300 °C are likely due to changes in the cation distribution, whereas above 300 °C, compositional fluctuations due to spinodal decomposition are evident. The exsolution mechanism has been investigated using energyfiltered transmission electron microscopy, which has allowed direct imaging of the compositional fluctuations consistent with the theoretical predictions of spinodal decomposition.

We have examined finely exsolved oxides of the hematite-ilmenite solid-solution series found in slowly cooled middle Proterozoic igneous and metamorphic rocks. These oxides impart unusually strong and stable remanent magnetization. Transmission electron microscopy (TEM) analysis shows multiple generations of ilmenite and hematite exsolution lamellae, with lamellar thicknesses ranging from millimeters to 1-2 nanometers. Rock-magnetic experiments suggest that the remanence is thermally locked to the antiferromagnetism of the hematite component of the intergrowths, yet is stronger than expected for a canted antiferromagnetic hematite or coexisting paramagnetic Fe-Ti- ordered (R 3) ilmenite. In alternating field experiments a stable magnetization is observed in these samples to fields of 100 to 120 mT, indicating that the natural remanent magnetization (NRM) is stable over billions of years. This feature has implications for understanding magnetism of deep rocks on Earth, or on planets like Mars that no longer have a magnetic field. Atomic-scale simulations of an (R 3) ilmenite lamella in a hematite host, based on empirical cation-cation and spin-spin pair interaction parameters, show that boundary regions of the lamellae are occupied by "contact layers" with a hybrid composition of Fe ions, intermediate between Fe 2+ -rich layers in ilmenite and Fe 3+ -rich layers in hematite. In this paper we review current data and explore further the nature of the interface.

The interfaces between fine-scale exsolution lamellae of hematite and ilmenite from an igneous rock in Rogaland, Norway have been studied by conventional transmission electron microscopy (TEM), high-resolution TEM, and energy-filtered TEM (EFTEM), to investigate the lamellar magnetism hypothesis for the origin of the unusual magnetic properties of this rock. Very fine hematite and ilmenite lamellae, less than 50 nm in length and parallel to (001) of their host, were abundant throughout the hemo-ilmenite sample. Dark-field and EFTEM observations indicated the hematite and ilmenite have very sharp structural and compositional interfaces with their hosts. The interfaces between the coarse hematite and ilmenite lamellae (length >1 μm) and their hosts have some interface dislocations to relieve elastic coherency strain. On the other hand, very fine lamellae (length

The oxygen fugacity f(O2)of the Earth's mantle is one of the fundamental variables in mantle petrology. Through ferric-ferrous iron and carbon-hydrogen-oxygen equilibria, f(O2) influences the pressure-temperature positions of mantle solidi and compositions of small-degree mantle melts. Among other parameters, f(O2) affects the water storage capacity and rheology of the mantle. The uppermost mantle, as represented by samples and partial melts, is sufficiently oxidized to sustain volatiles, such as H2O and CO2, as well as carbonatitic melts, but it is not known whether the shallow mantle is representative of the entire upper mantle. Using high-pressure experiments, we show here that large parts of the asthenosphere are likely to be metal-saturated. We found that pyroxene and garnet synthesized at >7 GPa in equilibrium with metallic Fe can incorporate sufficient ferric iron that the mantle at >250 km depth is so reduced that an (Fe,Ni)-metal phase may be stable. Our results indicate that the oxidized nature of the upper mantle can no longer be regarded as being representative for the Earth's upper mantle as a whole and instead that oxidation is a shallow phenomenon restricted to an upper veneer only about 250 km in thickness.

Background: Cobalt-ferrite nanoparticles (Co-Fe NPs) are attractive for nanotechnology-based therapies. Thus, exploring their effect on viability of seven different cell lines representing different organs of the human body is highly important. Methods: The toxicological effects of Co-Fe NPs were studied by in-vitro exposure of A549 and NCIH441 cell-lines (lung), precision-cut lung slices from rat, HepG2 cell-line (liver), MDCK cell-line (kidney), Caco-2 TC7 cell-line (intestine), TK6 (lymphoblasts) and primary mouse dendritic-cells. Toxicity was examined following exposure to Co-Fe NPs in the concentration range of 0.05 -1.2 mM for 24 and 72 h, using Alamar blue, MTT and neutral red assays. Changes in oxidative stress were determined by a dichlorodihydrofluorescein diacetate based assay. Data analysis and predictive modeling of the obtained data sets were executed by employing methods of Knowledge Discovery from Data with emphasis on a decision tree model (J48). Results: Different dose–response curves of cell viability were obtained for each of the seven cell lines upon exposure to Co-Fe NPs. Increase of oxidative stress was induced by Co-Fe NPs and found to be dependent on the cell type. A high linear correlation (R2=0.97) was found between the toxicity of Co-Fe NPs and the extent of ROS generation following their exposure to Co-Fe NPs. The algorithm we applied to model the observed toxicity belongs to a type of supervised classifier. The decision tree model yielded the following order with decrease of the ranking parameter: NP concentrations (as the most influencing parameter), cell type (possessing the following hierarchy of cell sensitivity towards viability decrease: TK6 > Lung slices > NCIH441 > Caco-2 = MDCK > A549 > HepG2 = Dendritic) and time of exposure, where the highest-ranking parameter (NP concentration) provides the highest information gain with respect to toxicity. The validity of the chosen decision tree model J48 was established by yielding a higher accuracy than that of the well-known “naive bayes” classifier. Conclusions: The observed correlation between the oxidative stress, caused by the presence of the Co-Fe NPs, with the hierarchy of sensitivity of the different cell types towards toxicity, suggests that oxidative stress is one possible mechanism for the toxicity of Co-Fe NPs. Keywords: Nanotoxicology, Cobalt-ferrite nanoparticles, Comparative cytotoxicity, Data mining, JRC.I.4-Nanobiosciences

The physiochemical properties of the carbon host matrix and their sulfur loadings play a major role in the electrochemical performance of lithium–sulfur batteries. A highly sulfur (S) loaded (75 wt%) carbon matrix (S/nitrogen rich carbon host matrix (NGC)) has been designed, with hierarchically organized micro/mesopore structures containing nitrogen and oxygen functional groups, and using metal oxide nanostructured templates. The S/NGC electrodes give reversible capacities of 868 and 666 mAh g−1 at C/5 current rates, with sulfur loading of 2.2 and 3.4 mg cm−2, respectively. Based on the advantages of the hierarchically organized porous structure and heteroatom doping, S/NGC electrode shows long cycling stability (0.03% capacity decay per cycle in the first 1000 cycles) with high coulombic efficiency (>99%), which is an improvement by a factor of two compared with a sulfur/graphene cathode. Further, the charge/discharge mechanism of the cell is investigated in detail by in situ Raman and ex situ X-ray photoelectron spectroscopy. The presence of nitrogen on the carbon support is found to make the bond formation easier between sulfur and oxygen functional groups existing at the carbon support, which is supposed to play a major role along with hierarchically organized porous structure, for the prevention of sulfur/polysulfides species dissolution to the anode side.

Rising demands for high-energy density Li-ion batteries require the development of new cathode active materials with enhanced specific capacity and energy, increased safety and reduced cost. Currently used high-cost metals, such as cobalt and nickel, need to be replaced with more abundant and less toxic elements. A Co-free cathode material with high-voltage and high-capacity has been developed in our labs. The lithium‐nickel‐manganese oxide with composition Li1+xNi0.5Mn1.5O4.0 (0-3. The cathode material shows a specific capacity of about 210 mA h g-1 in the potential window 2.4-4.9 V. The working mechanism involves two distinct voltage plateaus at 4.7 and 2.9 V vs. Li/Li+. Very good cycling stability is obtained for more than 200 cycles in half-cell. Compared to other high-capacity materials, such as lithium-manganese-rich layered oxides, their spinel integrated variants and the cation disordered materials [1-3], this material does not need an activation cycle; it shows good rate capability and low voltage hysteresis. In full-cell vs. graphite anode, a stable capacity of 160 mA h g-1 is reached. For full-cell application no electrochemical pre-treatment or structural activation has to be applied in order to achieve the full capacity; therefore, the material can be directly assembled vs. graphite anode. Cathode material features will be described, electrochemical performances in half- and full-cell will be presented and the influence of the operating voltage window will be shown. The effects of particle shape, grain architecture and structural features on the electrochemical behavior will be discussed. Phase transitions in the low-potential region have been studied by HRTEM, EELS and XRD and the involved mechanism will be discussed. Acknowledgements This work was supported by the German Federal Ministry of Education and Research (BMBF) in the project Li-EcoSafe (03X4636A). References [1] Thackeray, M.M.; Kang, S.-H.; Johnson, C.S.; Vaughey, J.T.; Benedek, R. and Hackney, S.A., J. Mater. Chem., 17 (2007) 3112 [2] Park, S.-H.; Kang, S.-H., Johnson, C.S., Amine, K.; Thackeray, M.M., Electrochem. Comm., 9 (2007) 262 [3] Yabuuchi, N.; Takeuchi, M.; Nakayama, M.; Shiiba, H.; Ogawa, M.; Nakayama, K.; Toshiaki Ohta, T.; Endo, D.; Ozaki, T.; Inamasu, T.; Sato, K.; Komaba, S., PNAS 12 (2015) 7650

Natural graphite (NG) is the dominant anode material for lithium ion batteries (LIBs) today, with a market share of approx. ~55%. With the continuous growth of portable, automotive, and other applications the total LIB market is expected to double within in the next decade. In view of this growth scenario, some prognoses predict supply bottlenecks of NG. Furthermore, the NG sources are geographically strongly concentrated today, which poses an immanent risk to supply security. In principle, the increasing demand for graphite as LIB anode material can be met by synthetic graphite, for which an upscaling of the production capacity is possible with economically justifiable effort within short time. Nonetheless, there are strong activities to develop new sources of NG. To benchmark the quality of these new materials, convenient and cost-effective characterization methods and facilities are required. Pristine flat flakes of NG are usually mechanically turned into spherical shapes (“spheroidization”) and coated with a thin film of amorphous carbon, in order to alleviate problems with exfoliation due to electrolyte solvent co-intercalation during lithium intercalation, to decrease the surface area and thus the irreversible capacity in the first charge/discharge cycle, as well as to increase density and thus the volumetric capacity. Recently, spheroidization is also more and more applied to synthetic graphite materials. Characteristic of the spheroidization procedure is that the yields are usually around 50% only. Any process improvement will therefore have a strong economic impact. The present work focuses on the lab-scale reconstruction of the industrial spheroidization and fractionation processes, using a rotor impact mill, an air jet sieve, and an air classifier. The aim is: to obtain a better understanding of the spheroidization process, by identifying critical process parameters and their influence on the resulting products (spherical graphite particles as well as by-products), to identify potentials for improving the process (especially in terms of yield), and to offer the opportunity to benchmark graphitic materials in lab-scale in comparison to industrially manufactured references. The obtained materials are analysed with regard to their electrochemical performance, as well as to their particle morphology (particle size distribution, particle shape, tap density and texture). The microstructure and texture is studied by SEM and FIB/SEM tomography, which provide information on the outer appearance in the nm scale and the open and closed porosity of the materials (Fig. 1). Acknowledgement: The authors are indebted to the German Federal Ministry of Education and Research (BMBF) for financial support (Project: Li-EcoSafe, contract no. 03X4636). Figure 1

Oligoclase and labradorite crystals have been experimentally replaced by albite in an aqueous sodium silicate solution at 600°C and 2 kbars. The replacement is pseudomorphic and is characterised by a sharp chemical interface which progresses through the feldspar while preserving the crystallographic orientation. Reaction rims of albite, up to 50 μm thick, can be readily achieved within 14 days. Re-equilibration of plagioclase in an 18O-enriched sodium- and silica-bearing solution results in oxygen isotope redistribution within the feldspar framework structure. The observed characteristics of the reaction products are similar to naturally albitised plagioclase and are indicative of an interface-coupled dissolution–reprecipitation mechanism. Chemical analyses demonstrate that the albitisation is accompanied by the mobilisation of major, minor and trace elements also including elements such as Al and Ti which are commonly regarded as immobile during hydrothermal alteration. The results contribute to developing our understanding of the close association between large-scale albitisation and secondary ore mineralisation which is common in nature. peerReviewed

The scope of this study was to evaluate the incidence and the eventual consequences of amniotic fluid aspiration (AFA) in cases of sudden infant death. Cases of sudden infant death syndrome (SIDS; n = 113: 39 females, 74 males; mean age 4.6 months) were compared to a control group of 39 cases of explained death (14 females, 25 males; mean age 5.6 months). In each case, sections of the lung stained with hematoxylin and eosin and with the immunohistochemical reaction 34BE12 specific for cytokeratins were available. The microscope slides were observed at x200 magnification and semi-quantitatively classified into four categories(-, +, ++, and +++). In both groups, rests of amniotic fluid could be observed up to the fourth month of life. The comparison between the two groups did not show any significant difference. In the SIDS group, immunohistochemical reactions with the antibodies CD68, MRP8, MRP14, 27E10, 25F9, CD3, CD20Cy, and CD45R0 were available for the lungs. Twelve cases with AFA were compared to a group of SIDS cases without AFA with similar age and pathological distribution to evaluate whether the presence of amniotic remnants induced inflammatory changes in the lungs. No differences emerged. This study shows that AFA is not a rare event. Even moderate to severe AFA does not necessary cause death. A correlation between AFA and SIDS could not be shown.

The aim of this work is to understand the mineral replacement mechanism occurring in the transformation from originally Cl-rich apatite and to hydroxyapatite found in south Norway. The hypothesis is that a fluid-mediated mineral replacement mechanism based on interface-coupled dissolution re-precipitation [1] was inducing the phase transformation.

Passivated iron nanoparticles (10-30 nm) have been synthesized by laser pyrolysis of a mixture of iron pentacarbonyl and ethylene vapors followed by controlled oxidation. The nanoparticles show a well-constructed iron-iron oxide core-shell structure, in which the thickness and nature (structure similar to maghemite, γ-Fe2O3) of the shell is found to be independent of the initial conditions. On the other hand, the composition of the core is found to change with the particle size from the α-Fe structure to a highly disordered Fe phase (probably containing C atoms in its structure). The dependence of the magnetic properties on the particle size, iron oxide fraction, and temperature was also investigated. In the case of smaller particles, the magnetic data indicate the existence at low temperature of a large exchange anisotropy field, the magnitude of which increases with decreasing temperature in correspondence with the freezing of magnetic moments in the oxide shell. © 2006 Wiley-VCH Verlag GmbH & Co. KGaA.

Analytical transmission electron microscopy is a proper method so as to uncover microstructure and composition of novel magnetic nanocrystals potentially used as biological markers. The focus of this study is the preparation and characterization of the (Fe 1− x Co x ) 1− y Pt y alloyed nanoparticles utilizing high-resolution transmission electron microscopy and dispersive X-ray analyses.

International audience; We have performed hydrothermal experiments with a crystalline microlite and a heavily self-irradiation-damaged (i.e., X-ray amorphous) betafite in a solution containing 1 mol/l HCl and 1 mol/l CaCl2 at 175 °C for 14 days. The well-crystalline microlite grains were partly (?5 10 ?m rim) replaced by a Ca and Na-poorer, defect pyrochlore phase with a larger unit-cell and a sharp chemical gradient at the interface (on a nm scale) to the unreacted core. The amorphous betafite grains (up to ?2 mm in diameter), on the other hand, were completely transformed into an intergrowth of different crystalline phases (polycrystalline anatase and rutile, a yet unidentified Nb Ta oxide, and a Y REE phase), showing complex non-equilibrium structures. Our experimental observations bear a remarkable resemblance to those made on natural samples. They indicate that the processes of the fluid pyrochlore interaction are influenced by self-irradiation structural damage and that thermodynamic equilibrium models can hardly be applied to adequately describe such systems.

Extended abstract of a paper presented at Microscopy and Microanalysis 2013 in Indianapolis, Indiana, USA, August 4 – August 8, 2013.

Extended abstract of a paper presented at MC 2007, 33rd DGE Conference in Saarbrücken, Germany, September 2 – September 7, 2007