Antiferrodistortive and ferroeletric phase transitions in freestanding films of SrTiO3
Epitaxially grown thin films are commonly used to strain engineer electronic properties by the choice of a substrate, and therefore do not match bulk properties (leading to properties that deviate from the bulk material). Free standing ultrathin oxide films are expected to preserve the bulk-like properties due to the absence of substrate influence. However, we show that this expectation is not fulfilled with ultrathin free standing SrTiO3, as they get ferroelectric at 80K.
Observing laser-induced recrystallization
Synchrotron X-ray diffraction sheds light on laser-induced local recrystallization .
Excitons coupling to octahedral tilts in Pb nano-perovskites
Excitons coupling to octahedral tilts in Pb nano-perovskites
Crystal field rules heavy fermion delocalization in SmCoIn5
Crystal field rules heavy fermion delocalization
"Core-shell" cathodes for high performance Li-ion batteries
“Li-rich Ni-rich” core-shell particles are engineered as layered cathode materials for high energy Li-Ion batteries, including a controllable outer "Li-rich Mn-rich" shell improving cyclability.
Mechanochromism of layered perovskites
The mechanochromism of hybrid 2D perovskites is probed at pressures compatible with practical applications
Direct mechanochemical synthesis of polyoxometalates
Polyoxomolybdates have been directly synthesized from basic reagents in a mechanochemical one-pot reaction.
Enhanced Stability of a Pyrophosphate cathode for Na-ion batteries
The structural changes of Na3.32Fe2.11Ca0.23(P2O7)2 during several charge discharge cycles is viewed by its powder pattern and selected cell parameter evolution.
X-rays illuminate the particle atomic structure of cyan light emitting 6-monolayers CsPbBr3 nanoplatelets by Total Scattering
A cyan light (492 nm) emitting colloidal suspension of CsPbBr3 nanoplatelets in a flask, together with the high-quality XRPD Total Scattering pattern of the suspension measured at the X04SA-MS beamline and the full-nanoparticle structure thereby inferred.
An iodine polymeric chain with tunable conductivity
The progressive hydrostatic compression of I2 and I3- units in an organic salt lead to a homoatomic polymeric chain. As the I---I distance collapses the covalent character of the interaction becomes more relevant, leading to a pressure-tunable increased conductivity.
HERCULES school 2019 at SLS
In the week of April 1-5 PSI welcomes 20 PhD students and postdocs taking part in the European HERCULES 2019 school on Neutron and Synchrotron Radiation. They will attend lectures and perform two days of practical courses at several beam lines of the Swiss Light Source.
Additive Manufacturing of High Entropy Alloys
Additive manufacturing of high-entropy alloys combines the mechanical properties of this novel family of alloys with the geometrical freedom and complexity required by modern designs. An approach to additive manufacturing of high-entropy alloys has been developed based on 3D extrusion of inks containing a blend of oxide nanopowders (Co3O4 + Cr2O3 + Fe2O3 + NiO), followed by co-reduction to metals, inter-diffusion and sintering to near-full density CoCrFeNi in H2. A complex phase evolution path is observed by in-situ X-ray diffraction in extruded filaments: the oxide phases undergo reduction and the resulting metals inter-diffuse, ultimately forming the desired fcc-CoCrFeNi alloy (see figure). Linked to this phase evolution is a complex micro-structural one, from loosely packed oxide particles to fully-annealed, metallic CoCrFeNi with 99.6 ± 0.1% relative density. CoCrFeNi micro-lattices are created with strut diameters as low as 100 μm and excellent mechanical properties at ambient and cryogenic temperatures.
Moving Atoms by Photodoping
Understanding how and how fast we can drive atoms to create a structural phase transition is of fundamental interest as it directly relates to many processes in nature. Here we show that a photoexcitation can drive a purely structural phase transition before the energy is relaxed in the material that corresponds to a “warmer” equilibrated state.
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.