People 27.08.2015 Candidate Quantum Spin Liquid in the Ce3+ Pyrochlore Stannate Ce2Sn2O7 We report the low-temperature magnetic properties of Ce2Sn2O7, a rare-earth pyrochlore. Our suscep- tibility and magnetization measurements show that due to the thermal isolation of a Kramers doublet ground state, Ce2Sn2O7 has Ising-like magnetic moments of ∼1.18 μB. The magnetic moments are confined to the local trigonal axes, as in a spin ice, but the exchange interactions are antiferromagnetic. 24.08.2015 Umbrella MoU Signed by 14 Parties The Memorandum of Understanding of the Umbrella Collaboration was signed by 14 parties: ALBA, DESY, Diamond Light Source Ltd, Elettra, EMBL Heidelberg, ESRF, European XFEL, HZB, ILL, Instruct Academic Services Ltd, KIT, PSI, STFC and SOLEIL. 21.08.2015 In Situ Serial Crystallography Workshop at the SLS The Macromolecular Crystallography group at SLS is organizing a three days workshop on in situ serial crystallography (http://indico.psi.ch/event/issx) between November 17 and 19, 2015. It will be dedicated in the presentation of a novel method facilitating the structure determination of membrane proteins, which are highly important pharmaceutical targets but are difficult to handle using 'classical' crystallographic tools. Designed for 20 Ph.D. students, postdocs and young scientists from both academia and industry, the workshop will consist of introductory lectures, followed by hands-on practicals on in meso or lipidic cubic phase (LCP) crystallization, on in situ serial crystallography data collection using a micro-sized beam and on data processing. 20.08.2015 New insight into receptor signalling A team of 72 investigators across 25 institutions including researchers from the Paul Scherrer Institut obtained the X-ray structure of a rhodopsinàarrestin complex, which represents a major milestone in the area of G-protein-coupled-receptor (GPCR), a protein family recognized in the award of the 2012 Nobel Prize in Chemistry. 17.08.2015 Terahertz laser light focused to the extreme There are limits to how short a flash of light can be – in both time and space. Researchers from the Paul Scherrer Institute (PSI) have now succeeded in reaching these physical limits and producing the smallest possible flash. To do so, they used terahertz light, which is physically related to visible light or radio waves, but differs in its wavelength. 17.08.2015 •Future Technologies •6 min Terahertz laser light focused to the extreme Further information aboutMaterials research Researchers from the Paul Scherrer Institute have managed to focus the light pulse terahertz laser at the limit of what is permitted by the classical laws of physics. This opens up new possibilities for studying the properties of materials. 10.08.2015 •Fundamentals of Nature •8 min New details of the transmission of stimuli in living organisms unveiled Further information aboutBiology Further information aboutMedical Science Researchers unveil new details of how cells in a living organism process stimuli. So-called G-proteins, which help conduct external stimuli that reach a cell into its interior, play a central role here. For the first time, the study shows which parts of the G-proteins are vital for their function. Researchers from the Paul Scherrer Institute PSI, ETH Zurich, the pharmaceutical company Roche and the British MRC Laboratory of Molecular Biology report their results in the journals Nature and Nature Structural and Molecular Biology. 07.08.2015 Element-Specific X-Ray Phase Tomography of 3D Structures at the Nanoscale Recent advances in fabrication techniques to create mesoscopic 3D structures have led to significant developments in a variety of fields including biology, photonics, and magnetism. Further progress in these areas benefits from their full quantitative and structural characterization. 07.08.2015 Nanoscale switch for vortex polarization mediated by Bloch core formation in magnetic hybrid systems Vortices are fundamental magnetic topological structures characterized by a curling magnetization around a highly stable nanometric core. 06.08.2015 •Future Technologies •8 min Magnets made of non-magnetic metals Further information aboutMaterials research Further information aboutSμS For the first time, an international research team has demonstrated how to generate magnetism in metals that aren’t naturally magnetic, such as copper. The discovery could help develop novel magnets for a wide range of technical applications. Crucial measurements to understand this phenomenon were carried out at PSI à the only place where magnetic processes inside materials can be studied in sufficient detail. 05.08.2015 Beating the Stoner criterion using molecular interfaces Only three elements are ferromagnetic at room temperature: the transition metals iron, cobalt and nickel. The Stoner criterion explains why iron is ferromagnetic but manganese, for example, is not, even though both elements have an unfilled 3d shell and are adjacent in the periodic table: according to this criterion, the product of the density of states and the exchange integral must be greater than unity for spontaneous spin ordering to emerge. 30.07.2015 •Energy and Climate •8 min Radioactive waste caught in a cement trap Further information aboutEnvironment Further information aboutNuclear energy In a deep geological repository, low and intermediate level radioactive waste from nuclear applications is solidified by cementitious materials for several thousand years. Researchers from the Paul Scherrer Institute and the Karlsruhe Institute of Technology have now demonstrated how cement limits the mobility of those radioactive substances. The new findings improve our understanding of the processes involved in this early phase of deep geological disposal. 30.07.2015 Evidence for Coexistence of Bulk Superconductivity and Itinerant Antiferromagnetism in the Heavy Fermion System CeCo(In1−xCdx)5 In the generic phase diagram of heavy fermion systems, tuning an external parameter such as hydrostatic or chemical pressure modifies the superconducting transition temperature. The superconducting phase forms a dome in the temperature-tuning parameter phase diagram, which is associated with a maximum of the superconducting pairing interaction. Proximity to antiferromagnetism suggests a relation between the disappearance of antiferromagnetic order and superconductivity. 21.07.2015 •Health Innovation •9 min Fighting tumours with protons Further information aboutMedical Science Further information aboutProton therapy Interview with Damien Charles WeberDamien Charles Weber has been the head and chief physician of the Centre for Proton Therapy, the only centre of its kind in Switzerland, since 2013. In this interview, he talks about the successes of proton therapy in cancer treatment and the objectives for the next few years in this field. 13.07.2015 A new class of chiral materials hosting magnetic skyrmions beyond room temperature Magnetic skyrmions are tiny, magnetic-spin vortices that can emerge in magnetic materials. Due to their nanometric size, skyrmions could be used to build extremely high density memory spintronics devices. However, stable skyrmions are not easy to find and control, and are usually only observed well below room temperature. 10.07.2015 High-Precision Vertical Linear Translation for Offset Mirrors The horizontal and vertical offset mirrors are key optical elements for the SwissFEL ARAMIS Beamline. The offset mirrors for example, are used to deflect and steer the x-ray beam into one of the end stations. As the sample position is about 60m from the mirror, very high demands are put on the mirror positioning system in order to deflect the x-ray beam on to the sample with a micro-meter precision. Therefore precise positioning of the mirrors is required, with specifications to move a load of up to 200kg by steps as small as 0.3µm. Not just the positioning must be precise, but also the stability for short term vibrations and long term drifts must be superior. 09.07.2015 Correlating the Core-Shell Composition and the Surface Structure to the Magnetic Properties for Magnetite-Maghemite Nanoparticles in the 5-15 nm Range Very small superparamagnetic iron oxide nanoparticles were characterized by innovative synchrotron X-ray total scattering methods and Debye function analysis, developed at the X04SA Materials Science beamline of SLS. 02.07.2015 A new class of chiral materials hosting magnetic skyrmions beyond room temperature Skyrmions, topologically protected vortex-like nanometric spin textures in magnets, have been attracting increasing attention for emergent electromagnetic responses and possible technological applications for spintronics. In particular, metallic magnets with chiral and cubic/tetragonal crystal structure may have high potential to host skyrmions that can be driven by low electrical current excitation. 02.07.2015 •Future Technologies •6 min Seven nanometres for the electronics of the future Further information aboutNanotechnology Further information aboutMaterials research Further information aboutSLS Researchers from the Paul Scherrer Institute have succeeded in creating regular patterns in a semiconductor material that are sixteen times smaller than in today’s computer chips. As a result, they have taken an important step closer towards even smaller computer components. Industry envisages structures on this scale as the standard for the year 2028. 01.07.2015 Superior Bifunctional Electrocatalytic Activity of Ba0.5Sr0.5Co0.8Fe0.2O3-δ/ Carbon Composite Electrodes: Insight into the Local Electronic Structure Using XAS it was demonstrated that carbon acts as an activity booster for Ba0.5Sr0.5Co0.8Fe0.2O3 oxygen reduction and evolution electrocatalyst promoting change of cobalt oxidation state. 29.06.2015 •Energy and Climate •6 min Particulate matter from modern gasoline engines damages our lungs Further information aboutEnvironment For years, studies have proved that fine dust from petrol engines can damage our health. Modern engine technology does not help, either, as researchers from the University of Bern and the Paul Scherrer Institute (PSI) reveal. 26.06.2015 Interplay between magnetic order at Mn and Tm sites alongside the structural distortion in multiferroic films of o-TmMnO3 We employ resonant soft x-ray diffraction to individually study the magnetic ordering of the Mn and the Tm sublattices in single-crystalline films of orthorhombic (o−)TmMnO3. The same magnetic ordering wave vector of (0q0) with q≈0.46 is found for both ionic species, suggesting that the familiar antiferromagnetic order of the Mn ions induces a magnetic order on the Tm unpaired 4f electrons. 23.06.2015 Crystallization of zirconia based thin films In pulsed laser deposition the use of a rectangular or elliptical beam spot with a non 1:1 aspect ratio leads to the so called flip-over effect. Here, the longest dimension of the laser spot results in the shortest direction of plasma plume expansion. 18.06.2015 Concept of a multichannel spin-resolving electron analyzer based on Mott scattering The spin of electron plays a crucial role in many physical phenomena, ranging from the obvious example of magnetism, via novel materials for spintronics applications, to high-temperature superconductivity. Spin- and angle-resolved photoelectron spectroscopy (SARPES) gives the most direct access to the spin aspects of the electronic structure, but the one-channel detection principle of all presently available SARPES spectrometers severely limits their efficiency. A team of Swiss and Russian scientists has developed a revolutionary concept of a multichannel electron spin detector based on Mott scattering as the spin selective process and imaging-type electron optics. 18.06.2015 Fermi Surface of Three-Dimensional La1−xSrxMnO3 Explored by Soft-X-Ray ARPES: Rhombohedral Lattice Distortion and its Effect on Magnetoresistance A research team led by scientists from the Swiss Light Source has for the first time established three-dimensional (3D) electronic structure of the perovskite compound La1−xSrxMnO3 connected with its colossal magnetoresistance. Instrumental for this study has been the use of the new experimental technique of soft-x-ray ARPES, available at the ADRESS beamline, with its intrinsically sharp definition of 3D electron momentum. 18.06.2015 Reduction of Mn19 Coordination Clusters on a Gold Surface The surface-induced changes of the oxidation state and magnetic properties of Mn ion clusters have been probed by X-ray absorption spectroscopy and X-ray magnetic circular dichroism. 17.06.2015 Mutual Independence of Critical Temperature and Superfluid Density under Pressure in Optimally Electron-Doped Superconducting LaFeAsO1−xFx The superconducting properties of LaFeAsO1−xFx under conditions of optimal electron doping are investigated upon the application of external pressure up to ∼23 kbar. Measurements of muon-spin spectroscopy and dc magnetometry evidence a clear mutual independence between the critical temperature Tc and the low-temperature saturation value for the ratio ns/m* (superfluid density over effective band mass of Cooper pairs). 12.06.2015 Spin-stripe phase in a frustrated zigzag spin-1/2 chain In strongly correlated electron systems periodic modulations on the nano-scale have typically been associated with competition between short- and long-range interactions, for example, between exchange and dipole-dipole interactions in the case of ferromagnetic thin films. Here we show that spin-stripe textures may develop also in antiferromagnets, where long-range dipole-dipole magnetic interactions are absent. 11.06.2015 Spin-stripe phase in a frustrated zigzag spin-1/2 chain Motifs of periodic modulations are encountered in a variety of natural systems, where at least two rival states are present. In strongly correlated electron systems, such behaviour has typically been associated with competition between short- and long-range interactions, for example, between exchange and dipole-dipole interactions in the case of ferromagnetic thin films. 10.06.2015 Controllable Broadband Absorption in the Mixed Phase of Metamagnets Combination of neutron scattering, muon spin relaxation, specific heat, ac and dc magnetization measurements, and electron magnetic resonance, reveals the ability of metamagnetic materials to absorb the electromagnetic radiation in an extremely broad frequency range. First page « First Previous page ‹‹ … 75 76 77 78 79 80 81 82 83 … Next page ›› Last page Last » Topic Overview
27.08.2015 Candidate Quantum Spin Liquid in the Ce3+ Pyrochlore Stannate Ce2Sn2O7 We report the low-temperature magnetic properties of Ce2Sn2O7, a rare-earth pyrochlore. Our suscep- tibility and magnetization measurements show that due to the thermal isolation of a Kramers doublet ground state, Ce2Sn2O7 has Ising-like magnetic moments of ∼1.18 μB. The magnetic moments are confined to the local trigonal axes, as in a spin ice, but the exchange interactions are antiferromagnetic.
24.08.2015 Umbrella MoU Signed by 14 Parties The Memorandum of Understanding of the Umbrella Collaboration was signed by 14 parties: ALBA, DESY, Diamond Light Source Ltd, Elettra, EMBL Heidelberg, ESRF, European XFEL, HZB, ILL, Instruct Academic Services Ltd, KIT, PSI, STFC and SOLEIL.
21.08.2015 In Situ Serial Crystallography Workshop at the SLS The Macromolecular Crystallography group at SLS is organizing a three days workshop on in situ serial crystallography (http://indico.psi.ch/event/issx) between November 17 and 19, 2015. It will be dedicated in the presentation of a novel method facilitating the structure determination of membrane proteins, which are highly important pharmaceutical targets but are difficult to handle using 'classical' crystallographic tools. Designed for 20 Ph.D. students, postdocs and young scientists from both academia and industry, the workshop will consist of introductory lectures, followed by hands-on practicals on in meso or lipidic cubic phase (LCP) crystallization, on in situ serial crystallography data collection using a micro-sized beam and on data processing.
20.08.2015 New insight into receptor signalling A team of 72 investigators across 25 institutions including researchers from the Paul Scherrer Institut obtained the X-ray structure of a rhodopsinàarrestin complex, which represents a major milestone in the area of G-protein-coupled-receptor (GPCR), a protein family recognized in the award of the 2012 Nobel Prize in Chemistry.
17.08.2015 Terahertz laser light focused to the extreme There are limits to how short a flash of light can be – in both time and space. Researchers from the Paul Scherrer Institute (PSI) have now succeeded in reaching these physical limits and producing the smallest possible flash. To do so, they used terahertz light, which is physically related to visible light or radio waves, but differs in its wavelength.
17.08.2015 •Future Technologies •6 min Terahertz laser light focused to the extreme Further information aboutMaterials research Researchers from the Paul Scherrer Institute have managed to focus the light pulse terahertz laser at the limit of what is permitted by the classical laws of physics. This opens up new possibilities for studying the properties of materials.
10.08.2015 •Fundamentals of Nature •8 min New details of the transmission of stimuli in living organisms unveiled Further information aboutBiology Further information aboutMedical Science Researchers unveil new details of how cells in a living organism process stimuli. So-called G-proteins, which help conduct external stimuli that reach a cell into its interior, play a central role here. For the first time, the study shows which parts of the G-proteins are vital for their function. Researchers from the Paul Scherrer Institute PSI, ETH Zurich, the pharmaceutical company Roche and the British MRC Laboratory of Molecular Biology report their results in the journals Nature and Nature Structural and Molecular Biology.
07.08.2015 Element-Specific X-Ray Phase Tomography of 3D Structures at the Nanoscale Recent advances in fabrication techniques to create mesoscopic 3D structures have led to significant developments in a variety of fields including biology, photonics, and magnetism. Further progress in these areas benefits from their full quantitative and structural characterization.
07.08.2015 Nanoscale switch for vortex polarization mediated by Bloch core formation in magnetic hybrid systems Vortices are fundamental magnetic topological structures characterized by a curling magnetization around a highly stable nanometric core.
06.08.2015 •Future Technologies •8 min Magnets made of non-magnetic metals Further information aboutMaterials research Further information aboutSμS For the first time, an international research team has demonstrated how to generate magnetism in metals that aren’t naturally magnetic, such as copper. The discovery could help develop novel magnets for a wide range of technical applications. Crucial measurements to understand this phenomenon were carried out at PSI à the only place where magnetic processes inside materials can be studied in sufficient detail.
05.08.2015 Beating the Stoner criterion using molecular interfaces Only three elements are ferromagnetic at room temperature: the transition metals iron, cobalt and nickel. The Stoner criterion explains why iron is ferromagnetic but manganese, for example, is not, even though both elements have an unfilled 3d shell and are adjacent in the periodic table: according to this criterion, the product of the density of states and the exchange integral must be greater than unity for spontaneous spin ordering to emerge.
30.07.2015 •Energy and Climate •8 min Radioactive waste caught in a cement trap Further information aboutEnvironment Further information aboutNuclear energy In a deep geological repository, low and intermediate level radioactive waste from nuclear applications is solidified by cementitious materials for several thousand years. Researchers from the Paul Scherrer Institute and the Karlsruhe Institute of Technology have now demonstrated how cement limits the mobility of those radioactive substances. The new findings improve our understanding of the processes involved in this early phase of deep geological disposal.
30.07.2015 Evidence for Coexistence of Bulk Superconductivity and Itinerant Antiferromagnetism in the Heavy Fermion System CeCo(In1−xCdx)5 In the generic phase diagram of heavy fermion systems, tuning an external parameter such as hydrostatic or chemical pressure modifies the superconducting transition temperature. The superconducting phase forms a dome in the temperature-tuning parameter phase diagram, which is associated with a maximum of the superconducting pairing interaction. Proximity to antiferromagnetism suggests a relation between the disappearance of antiferromagnetic order and superconductivity.
21.07.2015 •Health Innovation •9 min Fighting tumours with protons Further information aboutMedical Science Further information aboutProton therapy Interview with Damien Charles WeberDamien Charles Weber has been the head and chief physician of the Centre for Proton Therapy, the only centre of its kind in Switzerland, since 2013. In this interview, he talks about the successes of proton therapy in cancer treatment and the objectives for the next few years in this field.
13.07.2015 A new class of chiral materials hosting magnetic skyrmions beyond room temperature Magnetic skyrmions are tiny, magnetic-spin vortices that can emerge in magnetic materials. Due to their nanometric size, skyrmions could be used to build extremely high density memory spintronics devices. However, stable skyrmions are not easy to find and control, and are usually only observed well below room temperature.
10.07.2015 High-Precision Vertical Linear Translation for Offset Mirrors The horizontal and vertical offset mirrors are key optical elements for the SwissFEL ARAMIS Beamline. The offset mirrors for example, are used to deflect and steer the x-ray beam into one of the end stations. As the sample position is about 60m from the mirror, very high demands are put on the mirror positioning system in order to deflect the x-ray beam on to the sample with a micro-meter precision. Therefore precise positioning of the mirrors is required, with specifications to move a load of up to 200kg by steps as small as 0.3µm. Not just the positioning must be precise, but also the stability for short term vibrations and long term drifts must be superior.
09.07.2015 Correlating the Core-Shell Composition and the Surface Structure to the Magnetic Properties for Magnetite-Maghemite Nanoparticles in the 5-15 nm Range Very small superparamagnetic iron oxide nanoparticles were characterized by innovative synchrotron X-ray total scattering methods and Debye function analysis, developed at the X04SA Materials Science beamline of SLS.
02.07.2015 A new class of chiral materials hosting magnetic skyrmions beyond room temperature Skyrmions, topologically protected vortex-like nanometric spin textures in magnets, have been attracting increasing attention for emergent electromagnetic responses and possible technological applications for spintronics. In particular, metallic magnets with chiral and cubic/tetragonal crystal structure may have high potential to host skyrmions that can be driven by low electrical current excitation.
02.07.2015 •Future Technologies •6 min Seven nanometres for the electronics of the future Further information aboutNanotechnology Further information aboutMaterials research Further information aboutSLS Researchers from the Paul Scherrer Institute have succeeded in creating regular patterns in a semiconductor material that are sixteen times smaller than in today’s computer chips. As a result, they have taken an important step closer towards even smaller computer components. Industry envisages structures on this scale as the standard for the year 2028.
01.07.2015 Superior Bifunctional Electrocatalytic Activity of Ba0.5Sr0.5Co0.8Fe0.2O3-δ/ Carbon Composite Electrodes: Insight into the Local Electronic Structure Using XAS it was demonstrated that carbon acts as an activity booster for Ba0.5Sr0.5Co0.8Fe0.2O3 oxygen reduction and evolution electrocatalyst promoting change of cobalt oxidation state.
29.06.2015 •Energy and Climate •6 min Particulate matter from modern gasoline engines damages our lungs Further information aboutEnvironment For years, studies have proved that fine dust from petrol engines can damage our health. Modern engine technology does not help, either, as researchers from the University of Bern and the Paul Scherrer Institute (PSI) reveal.
26.06.2015 Interplay between magnetic order at Mn and Tm sites alongside the structural distortion in multiferroic films of o-TmMnO3 We employ resonant soft x-ray diffraction to individually study the magnetic ordering of the Mn and the Tm sublattices in single-crystalline films of orthorhombic (o−)TmMnO3. The same magnetic ordering wave vector of (0q0) with q≈0.46 is found for both ionic species, suggesting that the familiar antiferromagnetic order of the Mn ions induces a magnetic order on the Tm unpaired 4f electrons.
23.06.2015 Crystallization of zirconia based thin films In pulsed laser deposition the use of a rectangular or elliptical beam spot with a non 1:1 aspect ratio leads to the so called flip-over effect. Here, the longest dimension of the laser spot results in the shortest direction of plasma plume expansion.
18.06.2015 Concept of a multichannel spin-resolving electron analyzer based on Mott scattering The spin of electron plays a crucial role in many physical phenomena, ranging from the obvious example of magnetism, via novel materials for spintronics applications, to high-temperature superconductivity. Spin- and angle-resolved photoelectron spectroscopy (SARPES) gives the most direct access to the spin aspects of the electronic structure, but the one-channel detection principle of all presently available SARPES spectrometers severely limits their efficiency. A team of Swiss and Russian scientists has developed a revolutionary concept of a multichannel electron spin detector based on Mott scattering as the spin selective process and imaging-type electron optics.
18.06.2015 Fermi Surface of Three-Dimensional La1−xSrxMnO3 Explored by Soft-X-Ray ARPES: Rhombohedral Lattice Distortion and its Effect on Magnetoresistance A research team led by scientists from the Swiss Light Source has for the first time established three-dimensional (3D) electronic structure of the perovskite compound La1−xSrxMnO3 connected with its colossal magnetoresistance. Instrumental for this study has been the use of the new experimental technique of soft-x-ray ARPES, available at the ADRESS beamline, with its intrinsically sharp definition of 3D electron momentum.
18.06.2015 Reduction of Mn19 Coordination Clusters on a Gold Surface The surface-induced changes of the oxidation state and magnetic properties of Mn ion clusters have been probed by X-ray absorption spectroscopy and X-ray magnetic circular dichroism.
17.06.2015 Mutual Independence of Critical Temperature and Superfluid Density under Pressure in Optimally Electron-Doped Superconducting LaFeAsO1−xFx The superconducting properties of LaFeAsO1−xFx under conditions of optimal electron doping are investigated upon the application of external pressure up to ∼23 kbar. Measurements of muon-spin spectroscopy and dc magnetometry evidence a clear mutual independence between the critical temperature Tc and the low-temperature saturation value for the ratio ns/m* (superfluid density over effective band mass of Cooper pairs).
12.06.2015 Spin-stripe phase in a frustrated zigzag spin-1/2 chain In strongly correlated electron systems periodic modulations on the nano-scale have typically been associated with competition between short- and long-range interactions, for example, between exchange and dipole-dipole interactions in the case of ferromagnetic thin films. Here we show that spin-stripe textures may develop also in antiferromagnets, where long-range dipole-dipole magnetic interactions are absent.
11.06.2015 Spin-stripe phase in a frustrated zigzag spin-1/2 chain Motifs of periodic modulations are encountered in a variety of natural systems, where at least two rival states are present. In strongly correlated electron systems, such behaviour has typically been associated with competition between short- and long-range interactions, for example, between exchange and dipole-dipole interactions in the case of ferromagnetic thin films.
10.06.2015 Controllable Broadband Absorption in the Mixed Phase of Metamagnets Combination of neutron scattering, muon spin relaxation, specific heat, ac and dc magnetization measurements, and electron magnetic resonance, reveals the ability of metamagnetic materials to absorb the electromagnetic radiation in an extremely broad frequency range.