MaMaSELF Status Meeting 2014

21 May 2014, 16:00 → 24 May 2014, 18:00 Europe/Zurich

Main Lecture Hall (Hotel Rigi Kulm)

Erasmus Mundus Program, www.MaMaSELF.eu

Wednesday, 21 May

Arrival/Departure

On Arrival: Room allocation (students: double rooms)
On Departure: Clearing rooms at 8.30h, Returning your keys
(MaMaSELF does not make any hotel reservation outside May 21 to May 24, 2014)

1 Distribution of Badges and Workhop Material

2 Room Allocation: Double Rooms for students (choose your room mate)

Dinner/Lunch

Dinner/Lunch/Breakfast

Opening/Closing

Convener: Juerg Schefer (Paul Scherrer Institut)

3 Opening Address

Speakers: Prof. Philippe RABILLER (Université de Rennes 1), Prof. Serge Di Matteo, Prof. Werner Paulus (Université Montpellier 2)

Evening Sessions: Keynote Lectures I

Convener: Juerg Schefer (Paul Scherrer Institut)

4 Probing the multiferroic properties of the geometric frustrated CuCrO2 compound using neutron large scale facilities at Paul Scherrer Institut, Oak Ridge and Los Alamos

low-temperature properties in general, and the tunability of the magnetic structure through an electric field and the electric polarization through a magnetic field in particular. The most promising candidates for such controllable multiferroics have been found among the materials with inherent geometric magnetic frustration. Among these, the delafossite CuCrO2, which crystallizes in the rhombohedral R-3m space group, is a multiferroic compound with an apparent strong coupling of spin and charge. In contrast to other multiferroic compounds CuCrO2 shows a spontaneous electric polarization upon antiferromagnetic ordering without an accompanying structural phase transition, thus the spiral magnetic ordering alone breaks the inversion symmetry. The peculiar magnetic structure of CuCrO2 allows the direct quantitative analysis of the domain population. In our contribution, we present a detailed study on CuCrO2 single crystals using neutron diffraction in applied electric and magnetic fields. With the fields we were able to tune the multiferroic states in CuCrO2 and could directly relate them to the underlying domain physics. Surprisingly, the domain population is changed only slightly by the electric field and the observed multiferroic properties arise therefore from a multi-domain state. Further, the sign reversal of the electric polarization through a reversed electric field is not accompanied through domain re-distribution. This evidences the proposed coupling of the electric polarization to the chirality of the magnetic spiral. We will also show that the three domain state is driven by strain induced across domain walls and that therefore one- or two-domain state is a non-equilibrium state. The underlying mechanism is key to understand the multiferroic properties of CuCrO2.

Speaker: Dr Matthias Frontzek (Paul Scherrer Institut, Laboratory for Neutron Scattering)

Thursday, 22 May

Sunrise

Dinner/Lunch: Breakfast

Dinner/Lunch/Breakfast

Arrival/Departure: Welcom

On Arrival: Room allocation (students: double rooms)
On Departure: Clearing rooms at 8.30h, Returning your keys
(MaMaSELF does not make any hotel reservation outside May 21 to May 24, 2014)

Student Sessions: Early Morning Session I

Convener: Prof. Peter Müller-Buschbaum (TU München)

5 Low temperature synthesis of TiO2 thin films with micrometer-sized channels via wet imprinting

Hybrid solar cells based on inorganic semiconductors have attracted great attention in recent years as it has special advantages over the conventional fully inorganic or organic solar cells, such as stability, biocompatibility, tunable morphology and low production expense. Among all the inorganic semiconductors, titanium dioxide (TiO2) has been proved to be a promising candidate for the inorganic component of hybrid solar cells due to its unique optical and electrical properties. For photovoltaic applications, the performance of the solar cells strongly depends on the morphology of the titanium dioxide layer. And a low temperature routine of TiO2 layer fabrication is required for flexible substrates like polymers. Here we present a low temperature synthesis of TiO2 thin films via combining block copolymer assisted sol–gel templating with wet-imprinting technique. TiO2 thin films with several hundred nanometers thickness are obtained and channel-like superstructures are well fabricated. SEM measurements demonstrate foam-like structures on the surface and GISAXS measurements indicate mesoporous structures inside the film.

Speaker: Mr Tianyi Wang (TU München)

6 In situ growth of titania films by spray deposition for solid-state dye-sensitized solar cells

Titanium dioxide is a wide band gap transition metal oxide semiconductor with applications in photocatalysis, photovoltaic devices, sensing and biomedical applications. Of particular interest is the fabrication of mesoporous titania thin films for application in photovoltaic devices such as dye sensitized solar cells, due to cheap and easy manufacturing, the electronic properties and a high chemical stability. Morphology control of the mesoporous titania layer is tightly linked to the solar cell efficiency, because electron transport will strongly depend on morphology. With respect to application, it is important to expand the fabrication in laboratory to a large scale film preparation. A widely used technique for this purpose is spray coating. The current work presents a study on the morphology of mesoporous titania films prepared by spray coating. We use grazing incidence small-angle X-ray scattering (GISAXS) in-situ during spray coating. GISAXS provides quantitative information about changes in the size of the titania particles and the distance between them during spraying. From the analysis of the in-situ GISAXS data, the growth of the titania films is determined.

Speaker: Mr Herbert Caller (TUM)

7 Oxygen storage in CeO2/Pt: XAS and DFT studies

In the last decades, media have talked a lot about a very serious thematic as environmental and energetic problem. This thesis is going to show the study on CeO2 as one of the possible candidate for both cases. The importance of ceria is given by its ability to store and release oxygen reversible. Main purpose of this work is to understand low temperature oxygen storage capacity (LT OSC) mechanism and the related structure of the reduced ceria surface on the atomic scale. The sample used is CeO2 nanorods promoted with Pt nanoparticles at different chemical environments and temperatures and, as references, CeO2 from NIST (National Institute of Standards and Technology), CeO2 rods, CeAlO3, Ce2Zr2O7. The CeO2 is considered for Ce4+, CeAlO3 for Ce3+, and instead in Ce2Zr2O7 both Ce3+ and Ce4+ are present. There were performed HERFD XANES spectra at the Ce L1 and L3 edges measured at the SuperXAS beamline at SLS (PSI, Villigen, Switzerland) and soft X-ray absorption Max Lab II (Lund, Sweden) at I1011 beamline at Ce M4 and M5 edges and at O K edge. In order to study the LT OSC process theoretically the DFT simulations were carried out using pseudopotential plane wave approximation within VASP software. Following structures were considered used in simulations: pure CeO2 bulk, CeO2 (111) surface, Ce2O3 hexagonal and cubic, Ce11O20, Ce7O12 and 2x2x2 supercell of CeO2 with O vacancy. Atomic structure, DOS and bandstructure has been derived and then compared with experimental data.

Speaker: Luca Braglia (Torino University, Southern Federal University)

10:30 Coffee

Student Sessions: Later Morning Session I

Convener: Dr Matthias Frontzek (Paul Scherrer Institut, Laboratory for Neutron Scattering)

8 Halogen-bonded co-crystals for ferroelectric materials: synthesis, crystal growth and structural investigations

In crystal engineering, intermolecular interactions play a crucial role, and give the possibility to create co-crystals. One of these interactions is halogen bond. As an analogue to the hydrogen bonding, it is a non-covalent interaction between covalently bounded halogen atom and Lewis base. This interaction is essentially of electrostatic nature. Indeed, the electron cloud around halogen atom is anisotropically distributed, leading to a depletion of charge (+δ) in the prolongation of the C–Hal bond, called σ-hole, and a concentration of charge (–δ) in the equatorial zone. This polarization effect is strongest with iodine, with I > Br >> Cl >> F.[1] Accordingly, strong and linear interactions are found between iodinated molecules and Lewis bases acting as halogen bond acceptors. In order to vary the strength of halogen bonding, different iodinated molecules can be evaluated, as well as different Lewis base acceptors.[1-3] During the master thesis, series of co-crystals of two halogen bond donors, namely, N-iodosuccinimide and N-iodosaccharin[4,5] investigated by single-crystal X-ray diffraction. An intermolecular N–I•••N' interaction was identified in different co-crystals involving primary aliphatic, and aromatic amines. In all samples, the N–I•••N' interaction is linear and notably shorter than the sum of van der Waals radii. Depending on the donor and acceptor molecules, the N–I and I•••N' distances vary up to a point where they are almost equal. Co-crystals with N-iodosaccharin exhibit indeed strong halogen bonding, with the possibility for a neutral to ionic transition at low temperatures.

Speaker: Ms Olena Makhotkina (MaMASELF, Université de Rennes1, Rennes, France)

9 Acceleration of pyroclastic particles and high-speed impacts: numerical simulations.

A steel basketball pole was the only object left standing in one village, 3.5 km from the crater, after the 1982 eruption of El Chichón volcano (Mexico). The surface of the object contains micrometer-sized craters attributed to the impact of ash particles (Scolamacchia and Schouwenaars, 2009) . Such particles consisted mostly of glass and crystals (hornblende, plagioclase, pyroxenes) ranging in size between 80µm and 280µm. Using the Bishop-Hill-Mott formula for penetration, Scolamacchia and Schowenaars (2009) estimated the velocity of impacting particles in a range between 710-980m/s. Such values exceed those normally reported for the speed of density currents generated during volcanic eruptions and they were therefore attributed to the acceleration of particles by shock waves arising from a momentum transfer from the gas to the solid phase. Shock waves are commonly generated during explosive eruptions at the vent by rapid decompression of the eruptive mixture. These waves in some cases can be also caused by magma-water interaction or by inside density currents which come from rapid change in the solid load due to topographic irregularities. The aim of this work is to investigate numerically if following the passage of a shock the ash particles can achieve such high-speed values. Initially we supposed that our ash particles don't influence on the gas flow. They move in the front of a shockwave and have the same velocity as a gas. 1D problem of gas outflow to the void has been solved. It gives us the required parameters (mainly pressure) to obtain this high velocities. They will be used as a first assumption for CFD simulations. Further we studied the penetration of particles into steel plate. These simulations were made with a ANSYS AUTODYN code. We used particles with three different sizes(80 µm, 200 µm, 300 µm) and different shapes (spherical, cylindrical, and conical). The results were compared with real data obtained by T. Scolamacchia. It was found that for such small particles the shape has a great influence for penetrations. For particles with a small height to width ratio the rarefaction waves associating the incident shock wave destroy that particles before the penetration starts. For further studies we choose 2 simple shapes: sphere and cylinder (with H=2r). The last step would consist in 2D CFD simulation in INCA-CFD code. This will gave us more accurate parameters for shock waves acceleration. The results of these numerical simulations will be cross-checked with real experiments using a shock tube. Real volcanic CO2 and SO2 gas mixture in this experiments will be replaced by gases which meet requirements for conditions to use in the laboratory.

Speaker: Mr Alexandr Golubev (LMU)

10 Linear Dichroism in the Fe K-edge of Magnetite

Fe3O4 is a well known inverse spinel compound with numerous applications for e.g. MRI contrast enhancement, hyperthermia treatment, drug delivery, etc. With particle sizes on the nano –scale, magnetite becomes chemically active and its electronic and magnetic structure changes as a function of the size. An in situ probe of the Fe electronic structure is possible using hard X-ray spectroscopy where an Fe 1s core electron is excited to a level just above the Fermi energy. Such excitations are referred to as K absorption pre-edges. The excited state decays with a certain lifetime and the core hole is filled via several possible decay channels. A highly probable decay channel is the K alpha fluorescence where a 2p electron fills the 1s level emitting K alpha X-rays. By monitoring the K alpha fluorescence intensity as a function of the incoming photoexcitation energy we gain information on the absorption cross-section at the K pre-edges and hence the electronic structure. The exact nature of the pre-edges is poorly understood owing to the fact that three different Fe sites in magnetite contribute to the spectra. In order to elucidate the electronic transitions that give rise to the pre-edge we performed linear dichroism(LD) experiments where the relative orientations between crystal axes, X-ray polarization and magnetic field are varied. Based on the LD experimental results obtained from the bulk magnetite we assign spectral features to specific Fe sites and interpret the spectral changes that magnetite undergoes when its particle size is reduced to a few nanometers.

Speaker: Ms Hebatalla Elnaggar (MaMaSELF)

Dinner/Lunch: Lunch

Dinner/Lunch/Breakfast

Student Sessions: Early Afternoon I

Convener: Prof. Peter Müller-Buschbaum (TU München)

11 In-situ growth study of gold nano-domains on P3HT films for hybrid solar cells

For fabrication of a top electrode in a hybrid solar cell, a metal thin film is deposited on the organic hole transfer layer in the cell, and a polymer/metal interface is formed. To deposit the electrode layer, sputtering is preferred as compared with vapor-deposition method, because of the metal wetting behavior when it grows on the polymer, which leads to a better contacting between metal and polymer and a more homogenous metal electrode. In our experiment, by sputtering, a gold layer is deposited on poly-(3-hexylthiophene) (P3HT) thin films, both with and without Li+ doping. The polymer films are on Si substrates. To better understand the morphological evolution of the gold layer during the deposition process, in situ grazing incidence small-angle X-ray scattering (GISAXS) is applied. By analyzing the 2D GISAXS data from the in-situ measurements the growth models can be accessed. Two different growth models, 3D cluster growth and 2D layer by layer growth, appeared during the sputtering process. By analysis of horizontal line cuts from the 2D GISAXS data in-plane structures are probed. During the early stages of sputtering, the lateral growth rate of gold clusters is relatively high according to a dramatically change of the periodic distance, and the sizes of gold clusters are broadly distributed. With the increasing of sputtering time, the sizes of the gold clusters trend to become constant. The samples with and without doping exhibit slight differences in their morphological evolution. However, the trends of the morphological evolution are similar. The vertical growth rate of the gold films can be gained by analysis of vertical line cuts from the 2D GISAXS data. In the initial stage a smaller growth rate of sputtering on P3HT than directly on SiO2 substrate is found. Thus 3d cluster growth of gold particles on P3HT and gold diffusion in the P3HT layer also appeared.

Speaker: Ms wei liu (MaMaSELF)

12 Synthesis of surface-functionalized silica mesophases containing ionic groups

Silicate mesoporous materials have large surface area and high pore volume, tunable and uniquely distributed pore size within 2-50 nm and highly ordered mesostructures, and therefore they are expected to find applications in fields of adsorption, heterogeneous catalysis, electronics, separation and medicine. The aim of my research is to investigate the synthesis of functionalized mesoporous silicas containing ionic groups from ionic organoalkoxysilane precursors. The synthesized material were investigated by various strategies 1.Ordered silica functionalized supported imidazolium species: - by co-condensation within the synthesis medium of the alkoxysilane precursor of the silica mesostructures and ionic organoalkoxysilane [1]as co-structure directing agent to obtain the functionalized material after one step. The characterization is made by Liquid state NMR, Mass spectroscopy and Nitrogen sorption. 2.Ordered silica functionalized supported Amine species: - by co-condensation within the synthesis medium of the alkoxysilane precursor of the silica mesostructures and organoalkoxysilane containing a cationic functional group [2] as co-structure directing agent in the presence of different types of anionic surfactants[3]as structure directing agent. The characterization is made by Infrared spectroscopy, Mass spectroscopy and Nitrogen sorption. 3.Postsynthetic functionalization of silicas (Grafting):- by grafting the surface of the functionalized silicas with acid containing imidazole. The characterization is made by Solid state NMR, Nitrogen sorption and Thermo gravimetric analysis (TGA). We successfully synthesised functionalized mesoporous silicas with high surface area and large pore volume by different types of techniques. The surface properties of the materials were monitored via Nitrogen sorption and X-ray diffraction (XRD). The presence of ionic groups was proven via Solid state NMR, Nitrogen sorption and Thermo gravimetric analysis (TGA). .The formed materials will be tested for application in catalysis and separation. [1](a) M. Lombardo, S. Easwar, A. De Marco, F. Pasi, C. Trombini, Org. Biomol. Chem., 2008, 6, 4224-4229. (b) B. Gadenne, P. Hesemann, J.J.E. Moreau, Chem. Commun., 2004, 1768-1769. [2]T. Yokoi, H. Yoshitake, T. Tatsumi, Chem. Mater. 2003, 15, 4536-4538. [3] (a) C. Gao, H. Qiu, W. Zeng, Y. Sakamoto, O. Terasaki, K. Sakamoto, C. Chen, S. Che, Chem. Mater. 2006, 18, 3904-3914. (b) C. Gao, Y. Sakamoto, O. Terasaki, K. Sakamoto, S. Che, J. Mater. Chem., 2007, 17, 3591-3602.

Speaker: Mr Ahed Abouserie (MAMASELF)

13 Transient XAS measurement on platinum water-gas-shift catalysts

The water-gas-shift reaction is a promising route to increase H2/CO ratio of reformer gas in order to produce extremely pure H2 gas stream for other applications, such as fuel cells. H2O + CO ⇌ H2 + CO2 ∆H_298K=-41.13kJ/mol (1) Among all the supported catalysts containing nanoparticles of different noble metals, Pt exhibits great activity for water-gas-shift conversion [1]. Though supported noble metal nanoparticles catalysts have been widely investigated for decades, there are still competing models about the nature of the active sites. Supported by the fact that leached samples (without metallic Pt) had similar activity as unleached samples, it was suggested that non-metallic Pt species are responsible for the activity [2]. In contrast, other groups argued that metallic Pt was the only active sites [3]. It is our aim to resolve this discrepancy by in situ characterization under catalytic conditions, thus determining the structure-activity relationship of Pt catalysts. The experiments were carried out using the setup shown in Fig.1 (a) for XAS and simutaneous kinetic measurements with an on-line mass spectrometer. Samples were tested under water-gas-shift condition both with and without pre-treatments for reliable comparisons. QEXAFS enabled aquisition of spectra with time resolution of 1s and the structure of Pt nanoparticles was monitored during transient experiments. Figure 1(a) 6.8% CO, 22% H2O, 37%H2 and 8.5% CO2 were co-fed to the sampls in a capillary; water vapor was generated by flowing He through a water bubbler. Exit gas content was monitored by a mass spectrometer. Perpendicular to the gas flow, the X-ray beam passed through the samples and transmitted beam was detected by an ion chamber. Pt foil was used as a reference in this case; (b) XAS spectra of 1.5wt% Pt supported on Al2O3 at room temperature (red), 95°C(blue) and 200°C(green) under water-gas-shift condition. The spectra suggested that Pt nanoparticles were reduced at elevated temperatures under water-gas shift condition. Reference: 1.Panagiotopoulou, P. and D.I. Kondarides, Effect of the nature of the support on the catalytic performance of noble metal catalysts for the water–gas shift reaction. Catalysis Today, 2006. 112(1–4): p. 49-52. 2.Fu, Q., H. Saltsburg, and M. Flytzani-Stephanopoulos, Active Nonmetallic Au and Pt Species on Ceria-Based Water-Gas Shift Catalysts. Science, 2003. 301(5635): p. 935-938. 3.Pazmiño, J.H., et al., Metallic Pt as active sites for the water–gas shift reaction on alkali-promoted supported catalysts. Journal of Catalysis, 2012. 286(0): p. 279-286.

Speaker: Ms Binda Chen (Paul Scherrer Institut)

16:00 Coffee

Student Sessions: Later Afternoon I

Convener: Prof. Christine Papadakis (Technische Universität München)

14 Towards equilibrium in thin films from binary blends of diblock copolymers – AFM and GISAXS investigations

The self-assembly of block copolymer thin films may have a significant impact on the emerging nanotechnologies to create, for instance, ultrahigh density storage media or nanotemplates. In this perspective, solvent vapor annealing (SVA) is considered as a practical and reliable technique for the controlled modification of the structures in block copolymer thin films. In previous work, binary blends of compositionally symmetric poly(styrene-b-butadiene) diblock copolymers differing only in overall chain length were found to feature a one-phase lamellar structure after spin coating, contrary to what is known from bulk samples. For one of these blends, SVA was carried out and indeed induces macroseparation. Interestingly, perpendicular lamellae appear near the substrate and within the film, whereas parallel ones are found near the film surface. This phenomenon was observed by using atomic force microscopy (AFM) and grazing-incidence small angle X-ray scattering (GISAXS) as tools for investigation [1]. In the present project, we are using different solvents for SVA of the same film. These differ in quality and in selectivity to investigate the structural changes of this blend and to follow its pathway to equilibrium. The surface structures before and after SVA are determined using AFM, whereas the structural changes within the film during SVA are monitored using time-resolved GISAXS at CHESS, Cornell University. The results will show, in how far the interactions of the solvent with the diblock copolymer film can be used to tailor complex nanostructures. [1] J. Zhang, C. M .Papadakis et al., submitted

Speaker: Mr Mohamed Darweesh (Physics Department at Technische Universität München)

Evening Sessions: Keynote Lectures II

Convener: Prof. Wolfgang Schmahl (LMU)

15 An Introduction to Diamond Light Source and the material and magnetism beamline

In this presentation I will briefly presents the Diamond Light Source and the various research possibilities offered by the machine, then I will focus on the materials and magnetism beamline I16 illustrating the main features of the beamline. Finally I will present an example of research performed on I16 illustrating the kind of studies that we can perform.

Speaker: Dr Alessandro Bombardi (DiamondLight Source)

16 New possibilities for in-situ diffraction techniques with synchrotron radiation

abstract missing

Speaker: Dr Dmitry Chernyshov (Swiss Norwegian Beamline @ ESRF)

Dinner/Lunch

Dinner/Lunch/Breakfast

Evening Sessions: Keynote Lectures III

Convener: Dr SoHyun PARK (Section Crystallography, Dept. Earth & Environmental Sciences, LMU Munich, Germany)

17 Neutron Imaging - Material research in real space

Neutron imaging is a method that directly provides real-space information about the sample composition using neutrons as probing beam. In the standard configuration the resulting images represent the neutron shadow cast by the, for neutrons, semi-transparent sample. The basic principle is very similar to the more known X-ray radiography. The difference lies in the neutron matter interaction that provides a very different set of attenuation coefficients for the elements than the ones provided by X-rays. Radiography is the basic mode for neutron imaging, but the method is not limited to the acquisition of two-dimensional images. Computed tomography using neutron projection data makes it possible to reconstruct the three-dimensional distribution of attenuation coefficients in the sample. Depending on the installed instrumentation it is possible to reach voxel sizes of 13.5um for small samples, while it is possible to support samples with dimensions up to 250mm at lower resolution. For dynamic samples it is also possible to make real-time sequences. The acquisition rate is sufficient for many experiments with water in porous media. Most neutron imaging experiments are performed using radiography and tomography, but the use of optional energy selection devices in the beam makes it possible to perform Bragg edge imaging by acquiring images at different neutron energies. Neutron grating interferometry imaging is also a method that can provide additional information about the sample. The interferometer provides two additional images containing the differential phase shift and the dark field. The dark field images have proven useful in investigations of magnetic domains since it is sensitive to the small neutron scattering angles caused by the magnetic domain walls.

Speaker: Dr Anders Kaestner (Paul Scherrer Institut, NIAG)

Friday, 23 May

Sunrise

Dinner/Lunch: Breakfast

Dinner/Lunch/Breakfast

Student Sessions: Early Morning Session II

Convener: Sergio Di Matteo (Université Rennes 1)

18 Self-diffusion and roughness correlation in isotopic 56Fe/57Fe bilayers

Self-diffusion, a fundamental matter transport process in materials, is important for preparation, processing, and heat treatment of materials. To investigate the mechanism of self-diffusion, one needs to fabricate structures with proper isotope labeling. In our present work, isotope bilayers of 56Fe/57Fe with two different thicknesses with the purpose of comparing the diffusion process in samples with a plausible variation in the grain size were prepared by molecular beam epitaxy (MBE). The samples are of the following compositions 56Fe(2nm)/57Fe(2nm)/Pt(20nm) and 56Fe(5nm)/57Fe(5nm)/Pt(4nm), labeled as Fe5 and Fe2, respectively. The Pt layer on top of Fe layer is used to avoid oxidation. As-deposited samples were cut into six pieces (sample Fe5) and three pieces (sample Fe2) and were annealed at 473K for different annealing times. The thickness and roughness of the films were obtained using X-ray reflectivity (XRR). The lateral and longitudinal correlation length of roughness were investigated by x-ray diffuse scattering (XDS) and longitudinal off-set scans. Grazing-incidence small-angle x-ray scattering (GISAXS) was used to investigate the lateral correlation lengths which allow different bandpass of roughness as compared to that obtained from XDS. We have an interdiffused layer in between Pt and Fe layer even for the as-deposited specimens. The thicknesses and the scattering length densities of Fe, Pt and the interdiffused layers of the annealed samples remain fairly similar. Interestingly, two stages of evolution associated with a variation in the in-plane correlation lengths for each stage were identified from GISAXS measurement. Owing to the large difference in coherent neutron scattering length of 57Fe (2.3fm) and 56Fe (9.45 fm), neutron reflectometry (NR) can be effectively used to study the self-diffusion with annealing time. Additionally, using grazing incidence small angle neutron scattering (GISANS) we plan to investigate the change in correlation of Fe (domain correlations) in these systems. Multilayers of [56Fe(5nm)/57Fe(5nm)]5 and [56Fe(5nm)/57Fe(5nm)/Pt(5nm)]5 are being prepared and compared with the bilayers. Using our experimental chamber for in situ neutron scattering experiment we plan to compare the diffusion and change in correlation length with our ex situ results.

Speaker: Ms Jing Gong (Physik-Department E21, Technische Universität München, James-Franck-Strasse 1, 85748 Garching, Germany)

19 In situ characterization of ceria-based redox materials for solar thermochemical H2O and CO2 splitting

The main limitations to the widespread deployment of solar energy technologies have historically been their limited reliability and storage-related complexities. These correlated issues have been recently addressed through the development of solar-driven redox thermochemical cycles based on metal oxides, probably the most studied of which has been the Zn/ZnO cycle. All of them are based on a high-temperature endothermic reduction step employing concentrated sunlight, followed by a lower-temperature exothermic oxidation step closing the cycle. The concept is then to store the reduced material and reoxidize it whenever needed, for instance producing fuels. In this regard promising opportunities have been offered by a CeO2-δ redox cycle which exploiting the high O diffusivity and non-stoichiometry of this material ensures several technical and efficiency-related advantages over other cycles. This master thesis is then oriented toward the development and improvement of characterization techniques aimed to reach a deeper understanding of the processes involved in different Ce1-xMxO2-δ redox cycles and thus possibly to enable better-tailored chemical designs.

Speaker: Mr Simone Sala (MaMaSELF)

20 Study of the coalescence kinetic in oxide dispersion strengthened alloys

Compared to conventional alloys, oxide-dispersion-strengthened (ODS) ferritic alloys are promising candidate materials for the next generation of nuclear reactors (fusion and fast neutron reactors). They present excellent mechanical resistance at high temperature governed in part by the distribution of nano-oxides in the matrix. These materials are obtained by mechanical alloying and consolidated as rods by hot extrusion through a spinneret. Oxide precipitation (particles with different chemical compositions such as Y2O3, Y2Ti2O7 … may precipitate depending on the alloying elements) occurs during the hot consolidation step and during subsequent annealing at high temperature. However, the tensile or creep behavior of ODS steels varies with the oxide distribution. It is therefore of the utmost importance to control the oxide size distribution evolution during the different stages of the fabrication and during thermal treatments. With a view to understanding the mechanisms of formation and evolution of these particles, the oxides precipitation kinetics are studied as a function of nominal content of Y, Ti and O of the alloys using small-angle neutron scattering technique (SANS). In parallel, hardness measurements and neutron diffraction in situ tests under uniaxial loading are performed in order to correlate nano-precipitation and mechanical properties.

Speaker: Mr Marc-Antoine Thual (CEA/LLB_LMU)

10:00 Coffee/Tee

Student Sessions: Later Morning II

Convener: Prof. Werner Paulus

21 Formation of biomimetic carbonate crystals: Particle assembly vs. classical growth

Calcium carbonate is the most abundant mineral phase in biological hard tissues. It is today believed that biologically mediated carbonate minerals crystallizes from a precursor phase: amorphous calcium carbonate(ACC). During the transition of precursor ACC to crystallized skeletal material a hydrated ACC form goes through an anhydrous amorphous phase. Carbonate skeletal material is a hierarchical composite where at each scale level a mineral and an organic component are closely interlinked. Mineral nucleation and hard tissue formation are organic matter mediated. In order to understand the formation of carbonate biological hard tissues it is essential to investigate the transition from ACC to carbonate as well as the nucleation and crystallization of the carbonate mineral from the organic component. Thus, my master thesis project consists of two sub-project: 1. Synthesis and stabilization of ACC and its subsequent crystallization to calcite and/or aragonite. For this purpose I use the following methods: a. Precipitation of CaCl2 and Na2CO3 (mol ratio=1:1) in presence of magnesium additive[1]; b. Supersaturated Ca(OH)2 solution with polysorbate 20 incubated inside sealed desiccator containing ammonium carbonate; c. Precipitation of supersaturated Ca(OH)2 solution in presence of polysorbate 20 [2]. 2. The investigation of the crystallization of carbonate mineral from different gels that are model substances for the organic component in the biological hard tissues. I investigate the influence of mineral nucleation, formation and morphology of three different gels: a. Gelatin hydrogel[3], b. Agarose gel and c. Silica gel. [1] Fitriana Nindiyasari et al. in preparation. [2] Kyubock Lee, Wolfgang Wagermaierl et al., Self-assembly of amorphous calcium carbonate microlens arrays, Nature Communications, 2012, 3, 725. [3] Fitriana Nindiyasari, Lurdes Fernández-Díaz et al., Influence of Gelatin Hydrogel Porosity on the Crystallization of CaCO3, Crystal Growth Design 2014, 14(4), 1531-1542.

Speaker: Ms Quanling Zhang (Department of Earth and Environmental Sciences, LMU muenchen)

22 Non-stoichiometric transition metal oxides: exploring changes of structures and valance states by in situ neutron and synchrotron radiation.

Perovskite type oxides exhibiting ionic or mixed electronic/ionic conductivity are of considerable interest for potential application e.g. solid oxide fuel cells, battery electrodes and sensor materials. SrFeO2.5+x is an important candidate for this type of oxides. A specific lattice dynamics involving low energy phonon modes has been recently identified to be at the origin of high oxygen ion mobility already at low temperature [1]. Over the oxygen composition of 0≤x≤0.5, the SrFeO2.5+x system shows four distinct phases with x=0, 0.25, 0.375 and 0.5. The starting phase SrFeO2.5 has a oxygen deficient Brownmillerite type structure with 12-fold twinning and shows G-type anti-ferromagnetism where as the last candidate in this series SrFeO3 which can be obtained by electrochemical oxidation has a cubic Perovskite structure showing helimagnetism. The system SrFeO2.5+x has been extensively studied for last four decades and still it is of high interest because of the inherent complexity present in this system. Different space groups have been assigned to SrFeO2.5 e.g. Imma [2], Pbma [3] etc. but still they are highly debated. The aim of this master thesis is a detailed structure analysis of antiferromagnetic 12-fold twinned SrFeO2.5 single crystals using synchrotron and neutron diffraction and also to explore the phase diagram by following the electrochemically controlled oxygen intercalation reaction into SrFeO2.5 forming SrFeO3 by in situ single crystal synchrotron diffraction, performed in a specifically designed electrochemical cell. [1] Paulus, W.; Schober, H.; Eibl, S.; Johnson, M.; Berthier, T.; Hernandez, O.; Ceretti, M.; Plazanet, M.; Conder, K.; Lamberti, C. JACS, 2008, 130, 16080–16085. [2] Hodges, J.P.; Short, S.; Jorgensen, J. D.; Journal of Solid State Chemistry, 2000, 151, 190-209. [3] Auckett, J. E.; Studer A. J.; Sharma, N.; Ling, C. D.; Solid State Ionics, 2012, 225, 432–436.

Speaker: Mr Avishek MAITY (Technische Universität München / Université Montpellier 2)

23 Tuning of magnetic properties on CaFeO2.5/SrCoO2.5+δ heterostructures

CaFeO2.5 and SrCoO2.5 show an ordered deficient Perovskite structure and more specifically with a Brownmillerite type framework. Both are electronically insulating and antiferromagnetically ordered (G-type) with a Néel temperature of about 400°C. SrCoO3 can be obtained from SrCoO2.5 by electrochemical oxidation at ambient temperature, which itself shows metallic behaviour and it becomes ferromagnetic. CaFeO2.5 is chemically inert and has been reported to get oxidized only under extreme conditions, i.e. 1100°C and several GPa oxygen partial pressure (Po2). The present work aims to fabricate heterostructures based on alternating epitaxial thin films of CaFeO2.5 and SrCoO2.5 and to investigate the evolution of their magnetic properties during the selective oxidation of SrCoO2.5 to SrCoO3. The oxidation will be controlled electrochemically. Magnetic characterization will be investigated by SQUID and neutron reflectivity measurements. We expect interesting magnetic coupling as a function of δ, the orientation of the epitaxial films and temperature.

Speaker: Mr Rajesh Dutta (Paul Scherrer Institute / Université Montpellier 2)

Dinner/Lunch: Lunch

Dinner/Lunch/Breakfast

Student Sessions: Early Afternoon II

Convener: Dr Christoph Morkel (Physik-Department Technische Universitaet Muenchen)

24 Improving sound insulation on heating floors

ACOME had been created in 1932; the company has started to make cables for the army. It has become the first industrial cooperative in France. The company is now active on three major markets: automotive, telecom infrastructure and building solutions. In the building share, ACOME is selling 1.2 million m² of heating floor a year. A hydraulic heated floor has to be certified at the same time in mechanic resistance, in thermic insulation and in soundproofing. In 2000 appeared an acoustic insulation classification, which now allows a minimum of 15 dB impact sound reduction, while the best requires 22 dB and 8 dB for the aerial sound reduction. ACOME aims for the best in term of this classification. The mission has started by an approach on the certification, to benchmark the soundproofing in multiple fields and to have the fundamentals in acoustic. A focused study on the entire system as an acoustic point of view, find the right way to simulate, imagining a setup for measuring sound isolation. Finally, to propose innovative products for ACOME.

Speaker: Mr Alexis Keller (Master 2 MaMaSELF)

25 “Phase transitions in aperiodic composite mateials.”

Supramolecular or self-assembled materials often result from a subtle balance of weak intermolecular interactions yielding to a large variety of ordered and disordered phases with many different physical, chemical or mechanical properties. Alkane urea inclusion compounds (UIC) are molecular composite structures where a "host" framework of urea molecules accommodates "guest" alkane molecules as long chains loosely held in a honey-comb like hexagonal network of adjacent channels. Most of the alkane-UICs are incommensurate or aperiodic, which means that the ratio of the host and guest periodicities is not a rational number P/Q. As a consequence, very different types of short and long range ordering, as well as different phase transitions take place in these alkane-UICs just by changing the length of the alkane molecules. Even if these compounds are aperiodic by construction, periodicity can be recovered in superspaces of dimension greater than 3 and where full power of Fourier analysis can be used for crystallographic investigation. Alkane-UICs can be viewed as prototype compounds for which complementary use of Bragg and diffuse scattering on one hand and inelastic scattering (x-ray or neutron) and field gradient solid state NMR on the other hand can be carried on to study fluctuations around phase transitions in order to better characterize ordering mechanisms in organic crystals.

Speaker: Mr Ahmed Mohammed (Rennes University)

26 Low - temperature synthesis of nano-patterned TiO2 thin films by combining sol-gel synthesis and nano-imprinting

Nanostructured titania thin films are widely used in a variety of applications such as photovoltaics, photocatalysis, and gas sensing. For solar cell applications, a large surface-to-volume ratio of the inorganic semiconductor is needed, because the morphology influences charge carrier transport routes and the exciton dissociation, which occurs at the interface of the inorganic and the organic parts, and therefore the probabilities of electron-hole recombination. The optical, electrical, and catalytic properties of TiO2 could be tuned by its morphology. In the present work a low-temperature route is used to obtain a mesoporous titania thin films with a foam-like morphology, which is attractive for many applications requiring moderate use in energy input or low temperature processing. The synthesis combines sol-gel chemistry with block copolymers as structure directing templates. Using the nanoimprinting technique, an additional superstructure in the range of tens of nanometers is imprinted on the surface of the titania thin films to increase the surface area. To investigate the nanostructure of the thin films, scanning electron microscope (SEM) is used to get information about the surface of the films and grazing incidence small angle x-ray scattering (GISAXS) is used to get information from inside the thin films.

Speaker: Amr Abdelsamie (TU München)

27 Projects management about technical problematic on perfume bottle glass defects that may appear during manufacturing steps.

SGD, which was before Saint-Gobain Desjonquères, is a must of the bottling industry and has been making bottles for perfumery and pharmacy industry for more than 110 years. During those several years, the company has been gathering an unmatched know-how that makes it one of the market leaders. Glass production requires adjustment of different machines and monitoring throughout the production chain to prevent the formation of defects and remove it before the sending to customers . The defects can form in any part of the production and be explained by many facts because the glass is a very difficult mastered material. At this step of my internship, two different missions have been started: 1) One of the wishes of the company is to reduce “chipped / incised” defects because it is the first case of customer quality complaints in 2013 and it has increased significantly since 3 years. The aim is to focus on the root cause and the non-detection of this defect. A private company will help us to keep a good methodology and remain it in the subject framework. 2) The other remit of this internship will be to find a solution to control as best as possible the measurement of the tin layer dropped off during the heat treatment on the glass just before the annealing. It can cause some visible marks after some perfections. The first step is to get a good standardization of the machine and understand the limits of it with our glass use. The second one, in parallel, is to try to find another more accurate experimental technic.

Speaker: Mr Germain NOYER (SGD company trainee; Mamaself Erasmus student)

16:00 Coffee/Tea

Evening Sessions: Keynote Lectures IV

Convener: Karin Kleinstück (LMU/TUM)

28 Research in Industry

Research & development in the industry generally is project based. More fundamental projects relevant for two or more Business Units are managned on corporate level (Central Research), whereas applied research being closer to the market is normally carried out within a single business unit. Each R&D Project has to be commercially justified, taking into account investment needed, important risk factors, market size, time to market, protection of intelectual property, need for internal and external support, strategic fit. Throughout the project time these factors are reviewed at important milestones, and decision is taken to continue the project, to cancel it or to put it temporarily on hold. Furthermore, a certain portion of the researches time can be used in an informal way for so-called exploratory research. Besides the pure scientific aspects R&D in in the industry is subject to further important constraints: Commercial success (Return on Investment) Intelectual property (patent protection) Regulations (registrations, environmental aspects, working safety...) Industrial associations Production issues Need for inhouse and external Expertise. As a consequence the profile of a successful researcher comprises a solid scientific knowhow combined with communication skills, networking abilities, salesmanship, knowledge of important legalislations and sense of cultural issues. A multidisciplinary and international study program like the MaMaSelf is an excellent basis to develop the personal skills of the students. Summary Primary Authors: Dr. HATER, Wolfgang (BK Giulini GmbH) <wolfgang.hater@icl-pp.com>

Speaker: Dr Wolfgang Hater

29 Materials Research and Applications at the High Flux Neutron Source FRMII

An overview will be presented over research activities at the High Flux Neutron Source FRMII in the fields of materials research, industrial and medical applications. In three topics, special emphasis is given to the unique design of the FRMII reactor, to the process of silicon doping on an industrial scale and thirdly to the production of technetium, a radiopharmaceutical for medical applications, which is foreseen to start in near future at the FRMII.

Speaker: Dr Christoph Morkel (Tu München)

Dinner/Lunch: Dinner

Dinner/Lunch/Breakfast

Meetings

Consortium

free: free for all students

students

Saturday, 24 May

Dinner/Lunch: Breakfast

Dinner/Lunch/Breakfast

Student Sessions: Early Morning III

Convener: Dr Pieter Glatzel (ESRF)

30 In situ studies of New Energetic Materials for use in fuel cells proton Conducting

Solid oxide fuel cells (SOFC) working around 1000 ℃ have drawn a growing interest in the field of energy. To increase durability and reduce the cost of these systems, one way is to lower the operating temperature. As a result, an increasing attention is paid to proton conducting cells whose operating temperatures are between 300 and 600 °C. In particular, a great effort is devoted to improving the cathode. It is suggested that the layered pervoskites LnBaM2O4+d (Ln=lanthanide, M = Fe, Co) and Ruddlesden-Popper (RP) materials Sr3M2O7-d (M = Fe, Co) which exhibit large amount of oxygen vacancies are good candidates for this application. Indeed, the RP phases which were originally proposed as SOFC cathode due to their good oxygen diffusion react with water at room temperature (RT), which suggests the possibility of proton conduction in this family of compounds. However, the high reactivity in ambient conditions leads to the decomposition and should be prevented while allowing water insertion around 300 °C. In this project, new RP phase in which Sr is partially replaced by La, Sr3-xLaxM2O7-d, is prepared to increase the stability in ambient conditions. The samples as well as the layered pervoskites are heated in wet atmosphere (3-60% H2O/N2) to monitor water incorporation by thermogravimetric analysis (TGA). X-ray diffraction (XRD) is used to check the stability after heating in wet atmosphere and the structure modification related to possible water insertion into the oxygen vacancies. The RP phase La1.1Sr0.9MnO4+d which accommodates a large quantity of oxygen in its interstitial sites, as shown by neutron diffraction, is also being investigated by TGA and XRD to check whether it can accommodate H2O /OH- in these positions.

Speaker: Mr wenbin wu (University of Rennes1)

31 Phase Transitions in Telluride Materials by X-ray Diffraction and Neutron Scattering

After the discovery of topological insulators, a theoretical model of a new class of unconventional superconductors (topological superconductors) was predicted. One of the most promising materials is Pd doped IrTe2. In our work, we plan to map out the phase transition between the CDW and the normal phase, for temperature above 4K. The details of the CDW distortion will be analyzed in detail as a function of temperature for different concentration of Pd doping. Full x-T diagram will be obtained after performing neutron powder diffraction in the superconducting phase in the 0.5-4 K region.

Speaker: Ms Kosova Kreka (MaMaSELF)

32 Morphology changes of organic solar cells introduced via aging

Organic solar cells emerge as a promising energy resource due to its advantages and its developing efficiency, which have reached more than 10% in lab scale. However, there is still a big challenge to increase the solar cell lifetimes. Several mechanisms such as chemical and physical alteration have been proposed, but still there is a lack of understanding on morphology changes introduced by aging. This understanding is important because the morphology plays a crucial role at the photon to charge transformation mechanisms. In order to understand these mechanisms, we prepared the active layers of organic solar cells made from annealed poly(3-hexylthiophene-2,5-dyl) (P3HT) : phenyl-C61-butyric acid methyl ester (PCBM). These active layers are illuminated by different time under UV light in a UV oven. The morphology changes have been studied by using grazing incidence small angle X-ray scattering (GISAXS) and the absorption behavior has been studied by UV-VIS spectroscopy.

Speaker: Ms Efi Dwi INDARI (TUM)

Opening/Closing: Returning Keys of the Rooms, Clearing the rooms

10:05 Coffee/Tea

Evening Sessions: Keynote Lectures V

Convener: Dr SoHyun PARK (Section Crystallography, Dept. Earth &amp; Environmental Sciences, LMU Munich, Germany)

33 The Mn4Ca cluster in Photosynthesis - Where are the electrons?

The oxygen-evolving complex (OEC) located in the PSII membrane-bound protein in plant, algae, and cyanobacteria catalyses the water-oxidation reaction. The OEC, with four Mn and one Ca, couples the 4-electron chemistry of water oxidation with the one-electron photochemistry of the reaction center by sequentially storing oxidizing equivalents through five intermediate S-states (Si, i = 0 to 4), before one molecule of dioxygen is evolved. The Mn4CaO5 cluster provides a high degree of redox and chemical flexibility so that several oxidizing equivalents can be stored during the S-state cycle. To understand the mechanism of water oxidation in detail, it is crucial to know how the electronic and geometric structure of Mn4CaO5 changes during the catalysis and how the nature of the Mn-oxo bridges is affected by that. The S-states can be isolated by rapid freeze-quench after illumination but ideally the experiments are performed in a time-resolved manner at room temperature with in-situ illumination.

Speaker: Dr Pieter Glatzel (ESRF)

Opening/Closing

Convener: Prof. Wolfgang Schmahl (LMU)

34 Closing Remarks

Speaker: Prof. Serge di Matteo

35 Summary

Speakers: Prof. Philippe RABILLER (Université de Rennes 1), Prof. Werner Paulus

36 Closing

Speaker: Juerg Schefer (Paul Scherrer Institut)

Dinner/Lunch

Dinner/Lunch/Breakfast

Arrival/Departure: Departure

On Arrival: Room allocation (students: double rooms)
On Departure: Clearing rooms at 8.30h, Returning your keys
(MaMaSELF does not make any hotel reservation outside May 21 to May 24, 2014)

37 Clearing of rooms until 10am

38 Returning your keys