Dr
Marek Bartkowiak
(Paul Scherrer Institut)
16/09/2011, 12:15
Poster Session II (Friday)
Poster
The sample environment team at PSI provides expertise and support for systems to manipulate the sample or its environment during experiments at large scale facilities. A variety of cryostats, furnaces and cryo-magnets enable experiments under extreme conditions. Over the past years we have extended the experimental possibilities substantially. We will present a selection of new setups which...
Dr
S Kourtis
(Institute for Theoretical Solid State Physics, IFW Dresden, 01171 Dresden, Germany)
16/09/2011, 12:17
Poster Session II (Friday)
Poster
Excitation spectra of resonant inelastic x-ray scattering (RIXS) processes in one-dimensional Mott insulators are presented and discussed. The RIXS cross section of Hubbard and extended Hubbard models on finite half-filled chains is evaluated using exact diagonalization. The fundamental features of the obtained spectra reveal the different magnetic excitations occuring in indirect and direct...
Dr
R Kraus
(IFW Dresden, PF 270116, D-01171 Dresden, Germany)
16/09/2011, 12:19
Poster Session II (Friday)
Poster
We present a combined resonant inelastic x-ray scattering (RIXS) and electron energy-loss spectroscopy (EELS) study of the single layered manganite La1-xSr1+xMnO4 (LSMO). The RIXS planes were measured at the Mn K-edge at the ID 26 at the ESRF revealing the presence of intermediate and final states with different symmetries. A strong excitation is observed around 2eV for all doping levels by...
Dr
P Marra
(IFW Dresden, Dresden, 01069, Germany)
16/09/2011, 12:21
Poster Session II (Friday)
Poster
Resonant Inelastic X-ray Scattering (RIXS) has become nowadays one of the main experimental techniques to investigate elementary excitations in strongly correlated materials, and above all, cuprates. We describe a simple way to analytically calculate the scattering intensities in the case of copper L edge in the single ion picture. We use this result to obtain the scattering intensities of...
Mr
H Niwa
(University of Tokyo)
16/09/2011, 12:23
Poster Session II (Friday)
Poster
Carbon-based catalysts such as pyrolyzed Fe phthalocyane (FePc) show high oxygen reduction reaction (ORR) activities and are expected to be cathode catalyst alternative to Pt for polymer electrolyte fuel cells. To clarify the origin of the ORR activity, we have studied the electronic structure of the catalysts under vacuum condition. However, in situ observation of the electronic structure...
Dr
Jan Gui-Hyon Dreiser
(Paul Scherrer Institut)
16/09/2011, 12:25
Poster Session II (Friday)
Poster
Single-molecule magnets are exchange-coupled spin clusters showing slow relaxation of magnetization. In recent years, efforts have been intensified to increase the magnetization reversal barrier and thus enhance relaxation times by combining rare earth ions with transition-metal ions. Rare-earth ions exhibit very large magnetic anisotropies due to their strong spin-orbit coupling and their...
Ms
Yi Hu
(General Energy Research, Paul Scherrer Institute)
16/09/2011, 12:27
Poster Session II (Friday)
Poster
Orthorhombic rare earth manganates are materials showing a strongly coupled ferroelectric and magnetic order parameter at low temperatures. To better understand the influence of the MnO6 octahedron distortion on the magnetic ordering, the electronic structure of Mn in TbMnO3 and LuMnO3 thin films grown by pulsed laser deposition was investigated using XAS at the Mn K edge. XANES spectral...
Dr
Rajesh Vilas Chopdekar
(Paul Scherrer Institut)
16/09/2011, 12:29
Poster Session II (Friday)
Poster
In this work, we have used element-specific soft X-ray photoemission electron microscopy (X-PEEM) and polarized neutron reflectivity (PNR) to determine the influence of piezoelectric-ferroelectric BaTiO3 (BTO) on the magnetic properties of magnetostrictive ferromagnetic spinel CoFe2O4 and NiFe2O4 thin films. By using a combination of circular and linear dichroism spectro-microscopy as well as...
Mr
Matthias Bator
(Paul Scherrer Institut)
16/09/2011, 12:31
Poster Session II (Friday)
Poster
Magnetoelectrics, materials with ferromagnetism and -electricity in the same phase gained a lot of interest with the discovery of materials with improved properties. A strong coupling, caused by the magnetic-ordering induced polarization, has been found in orthorhombic rare-earth manganates. These materials are of large interest for basic research as well as for applications like...
Dr
Cinthia Piamonteze
(Paul Scherrer Institut)
16/09/2011, 12:33
Poster Session II (Friday)
Poster
The compound CuFeO2 has a delafossite structure where triangular layers of magnetic Fe3+ are separated by non-magnetic Cu1+ and O2- layers. CuFeO2 orders in a collinear four sublattice (4SL) structure below TN2=11K, with the magnetic moments along c. Associated with TN2 is a first order structural transition from hexagonal to orthorhombic. For temperature between TN1=14K and TN2 the system is...
Dr
Claudio Mazzoli
(Politecnico di Milano)
16/09/2011, 12:35
Poster Session II (Friday)
Poster
After pioneering experiments on the interaction between X-rays and spins, the advent of third generation synchrotron machines has definitely shown the versatility of Magnetic Resonant Elastic and Inelastic X-Ray Scattering in the investigation of magnetic materials.
In particular, the techniques benefits of chemical selectivity, high Q resolution and sensitivity to the angular part of...
Mr
Ravi Sura
(University de Rennes1 and PSI)
16/09/2011, 12:37
Poster Session II (Friday)
Poster
In order to investigate the effect of strontium on the oxygen diffusion in as grown single crystals of La2-xSrxCuO4ยฑฮด (x =0, 0.05, 0.1, 0.15) we first did Oxygen Isotope Back Exchange (OIBE) experiments between 40 0C to 1000 0C We proved that free oxygen mobility can be realized for x = 0, 0.05 already below 500 0C but is depressed for x = 0.1 and 0.15. This gives evidence that low...
Dr
Martin Mansson
(Laboratory for Solid State Physics, ETH Zurich)
16/09/2011, 12:39
Poster Session II (Friday)
Poster
We have performed an ARPES investigation of FeTe single crystals/films, as well as thin fims of the the novel superconductor FeTeOx [Y.F. Nie et al., Phys. Rev. B 82, 020508(R) (2010)]. Our results from the single crystals reflect the previously reported Fermi surface pocket around the X-point [(pi, 0)], possibly connected to a spin-density wave (SDW) order [Y. Xia, PRL 103, 037002 (2009)]....
Dr
Martin Mansson
(Laboratory for Solid State Physics, ETH Zurich)
16/09/2011, 12:41
Poster Session II (Friday)
Poster
BaCo2V2O8, belongs to a wide group of quasi-1D antiferromagnets (AF). The Q1D compounds display a variety of fascinating ground states governed by the strong spin-spin coupling along the 1D direction and a much weaker coupling along other directions. BaCo2V2O8 display a long-range AF order below TN=5 K and possibly short-range order all the way up to 30 K. Further, a novel type of field...
Dr
Martin Mansson
(Laboratory for Solid State Physics, ETH Zurich)
16/09/2011, 12:43
Poster Session II (Friday)
Poster
The title compound is a recently discovered heavy fermion material where the spacing between Ce-In planes is drastically increased. Consequently, CePt2In7 inherit a truly 2D electronic structure. It was recently discovered that CePt2In7 is not only AF (TN=5.3 K) at ambient pressure but also becomes SC under pressure with a maximum transition temperature Tc=2.1 K at P=3.12 GPa. At lower...
74.
Ion-texturing & Dynamics in Layered Compounds: From Electric Automobiles to Frustrated Magnetism
Dr
Martin Mansson
(Laboratory for Solid State Physics, ETH Zurich)
16/09/2011, 12:45
Poster Session II (Friday)
Poster
The drastic change from an insulating antiferromagnet to a superconducting state in cuprates, is probably the best example of how a slight change in carrier-density governs the magnetic/electronic properties of a material. Further, also ion-order within the intermediate charge-reservoir layers is of importance e.g. charge-order in the battery-type material NaxCoO2. In this compound, a novel...
Dr
Martin Mansson
(Laboratory for Solid State Physics, ETH Zurich)
16/09/2011, 12:47
Poster Session II (Friday)
Poster
The spin-web compound tricopper-tellurate Cu3TeO6, belongs to an intriguing group of materials where the magnetism is governed by 3d9 copper Cu(2+) ions. Cu3TeO6 has been sparsely experimentally studied and in fact only one
published investigation can be found regarding its magnetic properties. However, recently an inelastic neutron scattering (INS) study of the magnon dispersion in Cu3TeO6...
Dr
Martin Mansson
(Laboratory for Solid State Physics, ETH Zurich)
16/09/2011, 12:49
Poster Session II (Friday)
Poster
Recently, the mixed metal oxides of the form Li(Ni[1/3]Co[1/3]Mn[1/3])O2, have become the centre of attention as promising candidates for novel battery material. These materials have also revealed very interesting magnetic properties. The title compound, was from magnetometry measurements [1] found to be a percolating spin system interacting via AFM and FM superexchange interactions of...
Dr
Martin Mansson
(Laboratory for Solid State Physics, ETH Zurich)
16/09/2011, 12:51
Poster Session II (Friday)
Poster
For many years the interest for transition metal oxides (TMO) has been dominated by the layered copper (3d) oxides e.g. high-temperature superconductors. With developments in sample growing technique, scientists have started to move down the periodic table. Our work focuses on the related 5d TMO, Sr2IrO4, which is expected to display a spin-1/2 Kramers doublet ground state. However, while...
Dr
Martin Mansson
(Laboratory for Solid State Physics, ETH Zurich)
16/09/2011, 12:53
Poster Session II (Friday)
Poster
Many alkali transition-metal dioxides (AMO$_2$ with M =V, Cr, Fe, Co, and Ni) belong to the rhombohedral systems (space group R3m) crystallizing with the layered alpha-NaFeO2 structure. These compounds have been heavily investigated since the 1970s, originally due to their complex magnetic nature caused by the layered structure. Recently, the presence of both incommensurate (IC) AF order at 4...
Dr
Martin Mansson
(Laboratory for Solid State Physics, ETH Zurich)
16/09/2011, 12:55
Poster Session II (Friday)
Poster
When performing ARPES using low photon energies the experiments suffer from a number of limitations, e.g. a limited probing depth. In connection, there have been questions raised regarding the electronic structure amongst the layered cuprates being 2D or 3D in nature. To discern a possible kz-dependence using low photon-energies is a very tricky task. To interpret the data correctly one needs...
Dr
Masaki Kobayashi
(Paul Sherrer Institut)
16/09/2011, 12:57
Poster Session II (Friday)
Poster
Iron-based superconductors have attracted much attention because of the unexpected high transition temperatures. The mechanism of superconducting state in iron pnictides is considered to be different from high-Tccuprates. In contrast to two-dimensionality of Co-O plane in cuprates, hole-doped Ba1-xKxFe2As2(BKFA) has been reported to show the superconducting gap depending on kz...
Mr
Elia Razzoli
(Swiss Light Source, Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland)
16/09/2011, 12:59
Poster Session II (Friday)
Poster
The details of the electronic structure are important for understanding how superconductivity emerges in iron-based superconductors. The presence of long parts of Fermi surface (FS) connected by a fixed wave vector Q, the so-called FS nesting, has been proposed to be the driving force for the formation of the Spin Density Wave (SDW), and it may also produce the pairing interaction for...
Dr
Steven Johnston
(IFW Dresden)
16/09/2011, 13:01
Poster Session II (Friday)
Poster
Continued advancements in RIXS instrumentation have significantly increased the resolution of these experiments. As a result, features within 60-100 meV of the elastic line are becoming resolvable and recent experiments at the oxygen-K edge of the quasi-1D edge-shared cuprate Ca_{2+x}Y_{2-x}Cu_5O_{10} have uncovered detailed peak structure near the elastic line. In this poster we interpret...
Ms
Stephanie Stevenson
(Paul Scherrer Institut)
16/09/2011, 13:03
Poster Session II (Friday)
Poster
The main goals of this study are a systematic study and subsequent optimisation of microwave assisted magnetisation switching in magnetic structures. Stroboscopic time-resolved imaging of resonant magnetic eigenmodes and the detection of switching events are carried out with energy and polarisation dependent Scanning Transmission X-ray Microscopy at the PolLux beamline of the Swiss Light...
Mr
Jan Nowakowski
(Laboratory for Micro and Nanotechnology, Paul Scherrer Institut)
16/09/2011, 13:05
Poster Session II (Friday)
Poster
Using X-ray magnetic circular dichroism (XMCD), we present conclusive evidence that the spin of an organometallic molecule coupled to a ferromagnetic substrate can be switched between magnetic off and on states by a chemical stimulus. This is achieved by nitric oxide (NO) functioning as an axial ligand of cobalt(II) tetraphenyl-porphyrin (CoTPP) ferromagnetically coupled to nickel thin-film...
Mr
Martin Haag
(Paul Scherrer Institute, CH-5252 Villigen, Switzerland)
16/09/2011, 13:07
Poster Session II (Friday)
Poster
Polarized protons have a strong spin dependent interaction with neutrons and offer an interesting alternative to a polarized 3He spin filter. A concept for a polarized proton spin filter based on a rather new scheme of dynamic nuclear polarization (DNP) employing photoexcited triplet states, has been realized. It requires neither high fields nor very low temperatures to achieve high proton...
Dr
Anton Plech
(Institut fรผr Synchrotronstrahlung, KIT)
16/09/2011, 13:09
Poster Session II (Friday)
Poster
Laser ablation synthesis in solution is a versatile technique to produce nanoparticles of a large variety of materials. Understanding the involved mechanisms implies the study of the kinetics on the nanoscale with high time resolution.
A time gating technique has been applied to resolve the particle formation process with small angle scattering with a resolution of tens of microseconds. The...
9.
Operando fluorescence x-ray absorption spectroscopy studies of proton-exchange membrane fuel cell
Dr
Ilya Sinev
(Ruhr-University Bochum, Bochum, Germany)
16/09/2011, 13:11
Poster Session II (Friday)
Poster
A test setup for membrane-electrode-assemblies (MEAs) of proton exchange membrane fuel cells which allows in-situ fluorescence X-ray absorption spectroscopy studies of one electrode with safe exclusion of contributions from the counter electrode is described. Interference by the counter electrode is excluded by geometry in which the incoming beam has a small angle of incidence with the...
Mr
Alan Farhan
(PSI)
16/09/2011, 13:13
Poster Session II (Friday)
Poster
Artificial spin ice systems, consisting of two-dimensional arrangements of single-domain nanomagnets, allow the study of frustration and emergent magnetic monopoles [1, 2]. Synchrotron x-ray photoemission electron microscopy allows direct imaging of the magnetic state of each nanomagnet, having moments pointing in one of two orientations parallel to their long axis.
Our recent studies of the...
Dr
Arndt Remhof
(Empa)
16/09/2011, 13:15
Poster Session II (Friday)
Poster
Lithium borohydride (LiBH4) is an ionic crystal, consisting of (Li)+ cations and (BH4)- anions. It undergoes an order/disorder transition at 380 K. The dynamic disorder of the HT phase originates from rotational jumps of the (BH4)- anions. The transition is accompanied by an increase of Li ionic conductivity by more than 3 orders of magnitude.
The HT phase of LiBH4 can be stabilized by...
Qianli Chen
(Empa)
16/09/2011, 13:17
Poster Session II (Friday)
Poster
Proton conductors are promising solid electrolyte materials for ceramic fuel cells operating at intermediate temperature. Protons are introduced in the form of water to those oxygen defected sites.
We found by electrochemical impedance spectroscopy at high pressure that compressing the lattice decreases proton conductivity, which indicates that the protons need "space" to move freely in the...
Dr
S Chodankar
(Paul Scherrer Institut)
16/09/2011, 13:19
Poster Session II (Friday)
Poster
Two surfaces in contact are found in everyday life. For hydrophilic surfaces in contact, the natural presence of a confined layer of water in the narrow gap between them has important implications for geochemical and biological processes such as swelling of clays and diffusion of water through nanopores. Numerous surface force experiments have been performed on such systems. However, force...
Mr
Daniel Frรถhlich
(Universitรคt Mainz)
16/09/2011, 13:21
Poster Session II (Friday)
Poster
Until now the problem of high-level nuclear waste storage has not been solved. Argillaceous rocks such as Opalinus Clay (OPA) are considered by several European countries as a potential host rock formation for nuclear waste repositories. With respect to the long term storage of spent nuclear fuel, 237Np will be one of the main contributors to the radiotoxicity of this waste material. To...
Mr
Daniel Frรถhlich
(Johannes Gutenberg University Mainz), Dr
Daniel Grolimund
(PSI), Mr
Jakob Drebert
(Johannes Gutenberg University Mainz), Dr
Samer Amayri
(Johannes Gutenberg University Mainz), Prof.
Tobias Reich
(Johannes Gutenberg University Mainz), Mr
Ugras Kaplan
(Johannes Gutenberg Universitรคt Mainz)
16/09/2011, 13:23
Poster Session II (Friday)
Poster
Plutonium will be a major contributor to the radiotoxicity of high-level nuclear waste after a storage time of more than 1,000 years due to the long half-lives of Pu-239, Pu-240, and Pu-242. Argillaceous rocks are under consideration as potential host rock formation for the construction of high-level nuclear waste repositories by several European countries, i.e., Belgium, France, Germany, and...
Mr
Cyprian Mieszczynski
(Paul Scherrer Institute)
16/09/2011, 13:25
Poster Session II (Friday)
Poster
Uranium dioxide nuclear fuel, UO2, with fissile 235U is normally used in commercial power plants. Fission of 235U generates light and heavy fission fragments and disturbs both cation-cation and cation-anion network in the fuel matrix. Uranium dioxide can also exist as a hyper-stoichiometric UO2+x following oxidation. Nonstoichiometry in UO2 fuel may result a decreased thermal conductivity,...
Dr
Andreas Voegelin
(Eawag)
16/09/2011, 13:27
Poster Session II (Friday)
Poster
Silver nanoparticles (Ag-NP) are used in an increasing range of consumer products. They are mainly released into the environment via their discharge into sewers and after passing through wastewater treatment plants (WWTP). To determine the risks for aquatic environments arising from the use of Ag-NP, data on their fate in sewers and WWTPs are required. We recently studied the transformation...
Mr
Andreas Winter
(Univesity of Bielefeld)
16/09/2011, 13:29
Poster Session II (Friday)
Poster
Two-dimensional (2D) carbon nanomaterials, e.g., graphene, graphene oxide, carbon nanosheets and ultrathin polymeric films have recently received an enormous attention due to their potential for use in electronics, chemical or biological sensors and filters, nanocomposite materials, etc. Most of these applications require lithographic patterning of these 2D carbon materials with the nanoscale...
Annick Froideval
(High Temperature Materials, LNM / NES, Paul Scherrer Institute, 5232 Villigen PSI, Switzerland)
16/09/2011, 13:31
Poster Session II (Friday)
Poster
Ferritic oxide dispersion strengthened (ODS) steels are considered as candidate materials for fuel claddings in Generation IV nuclear energy systems. Amongst their prerequisite properties, ODS steels have to retain their dimensional stability over the operating conditions targeted for this next generation of nuclear reactors. Mechanical testing is thus necessary to ascertain that these...
Dr
A Idhil
(Paul Scherrer Institut, 5232-Villigen-PSI, Switzerland)
16/09/2011, 13:33
Poster Session II (Friday)
Poster
We investigate irradiation damage mechanisms and changes in microstructure upon ion-beam implantation of the model Fe1-x Crx alloys, with x up to 20%. Fe+-beam implantation simulates the effect of neutron irradiation with respect to formation and evolution of atomic displacement cascades. The ion-irradiated samples are not activated and can be easily handled as non-radioactive specimens. We...
Ms
Ana Maria Balan
(Swiss Light Source, Paul Scherrer Institut)
16/09/2011, 13:35
Poster Session II (Friday)
Poster
Increasing the storage density in future magnetic memory devices to the ultimate limit will require to address information at the level of individual nanoparticles. However, at small sizes thermal excitations can lead to undesired fluctuations of the magnetization and will affect their response to magnetic fields. In this contribution we use photoemission electron microscopy (PEEM) together...
Prof.
Bernd Schรถnfeld
(ETH Zรผrich), Dr
Markus Engelke
(ETH Zรผrich)
16/09/2011, 13:37
Poster Session II (Friday)
Poster
The microstructure of the bulk and surface of Ni-Pt alloys has attracted much interest over the years. For Ni-Pt surfaces, the segregation reversal is the most striking feature, with Ni enrichment for the top layer of a (110) surface and Pt enrichment for the top layer of (110) and (111) surfaces. Strong ordering for nearest neighbors and the different strength of Pt segregation into different...
Ms
Suzanne Visser
(MSc)
16/09/2011, 13:39
Poster Session II (Friday)
Poster
Suzanne Visser (PSI), M. Furger (PSI), U. Flechsig (SLS,PSI), K. Appel (DESY), A. S. H. Prevot (PSI) and U. Baltensperger (PSI)
Ambient aerosol samples were taken in several megacities (e.g. Paris, Los Angeles) with a Rotating Drum Impactor (RDI). The RDI sampled aerosol particles with a volumetric flow of 16.6 l min-1 (1 m3 h-1) and particle size segregation in the ranges of 10-2.5 ฮผm,...
