PLEASE NOTE SURFACE DIFFRACTION IS TEMPORARILY CLOSED, NO APPLICATIONS WILL BE ACCEPTED FOR THIS STATION - March 2017
POWDER DIFFRACTION IS INSTEAD NORMALLY OPEN
MS - X04SA: Materials Science
|Energy range||5 - 38 keV|
|Flux (10 keV)||2.5 x 1013 ph/s/0.4 A|
|Focused spot size||130 µm x 40 µm (1:1 focussing)|
General description and specifications
We welcome applications for beamtime as for the normal non PX schedule.
A detailed description of the beamline from the undulator source to the endstations is available in this J. Synch. Rad. paper (open access). Please cite this paper in all publications that include in any part data recorded at the MS beamline.
The beamline sequentially serves two endstations, described briefly here:
Nicola Casati and Antonio Cervellino. The MS Powder diffractometer works in Debye-Scherrer geometry and is equipped with a unique solid-state silicon microstrip detector, called MYTHEN (Microstrip sYstem for Time-rEsolved experimeNts), an outstanding in-house PSI detector group development (Bernd Schmitt, group leader and Anna Bergamaschi, MYTHEN II development).
The MYTHEN II detector is a general-purpose detector, with maximum resolution of 3.7 mdeg in 2θ, and very high efficiency and rapid acquisition times, with its simultaneous covering of 120 deg 2θ. This detector is particularly useful when either the scattering power is very low, or the acquisition times must be very short. It is therefore particularly suitable for time-resolved in-situ non-ambient XRPD and applications to the study of radiation sensitive materials, like organic compounds. MYTHEN II is also ideal for Industrial Applications of XRPD, particularly in the field of pharmaceuticals.
Several sample environments are available at the MS-PD station, controlling sample temperatures from 5 K to 1800 K, under gas and at high pressure, all interfaced with the MYTHEN II acquisition software. For a detailed list see here.
At the MS-PD station it is also possible to perform SR-XRPD experiments in combination with neutron PD experiments, the latter performed at the PSI Neutron facility SINQ facility. Once a year, users can submit joint XRPD and neutron-PD proposals via the so-called X-rays and neutrons (x+n) channel and if the proposal is accepted, the joint X+n beamtime allocation is coordinated by the SLS and SINQ beamline scientists (Nicola Casati and Antonio Cervellino at the SLS-MS and Denis Sheptyakov and Vladimir Pomjakushin at SINQ) so to sequentially perform the experiments. The joint X+n user operation is now a mature project with regular calls on Feb 15 each year, beamtime is allocated whenever possible and not necessarily at the same time in the two facilities. It is presently limited to crystallographic applications and only involves the SLS-MS beamline Powder Station and the SINQ HRPT laboratory.
The detector system is the PILATUS II novel photon-counting 2-D pixel detector, consisting of 486 x 195 pixels, each pixel subtending 0.0086o x 0.0086o. It also provides unsurpassed signal-to-noise ratios due to its zero electronic background noise, and has an excellent point spread function. The present maximum frame rate is 200 Hz. Typical surface diffraction experiments include recording crystal truncation rods, superstructure rods, reflectivity curves, in-plane diffraction, grazing-incidence small-angle scattering experiments, and time-resolved studies.
Current Highlights and News
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.
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 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.