Transition énergétique

Cu diimine complexes present a noble metal free alternative to classical Ru, Re, Ir and Pt based photosensitizers in solution photochemistry, photoelectrochemical or dye-sensitized solar cells. Optimization of these dyes requires an understanding of factors governing the key photochemical properties: excited state lifetime and emission quantum yield. Using pump-probe XAS and DFT calculations we have explored the involvement of exciplex formation in the deactivation of the photoexcited state.

Muons are particles with a spin of 1⁄2 that can be implanted into a wide range of condensed matter materials to act as a local probe of the surrounding atomic environment. Measurement of the muon’s precession and relaxation provides an insight into how it interacts with its local environment. From this, unique information is obtained about the static and dynamic properties of the material of interest ...

After several years of loyal and reliable services during heavy duty operation in a reactor, nuclear fuel must be discharged and go into retirement. For Switzerland, the final place of retirement is planned to consist of a deep geological repository where the used nuclear fuel will be disposed. Before the repository is constructed, the used fuel will need to be stored in wet pools and/or dry storage casks.

During all this time, safe handling of the fuel will remain the top priority for operators and regulators. To gain better knowledge on the relevant phenomena which could potentially affect the fuel thermo-mechanics and safety characteristics during long storage periods as well as to allow predicting their evolution, simulation models are being developed at PSI within the DRYstars project.

A first milestone was recently achieved with the development of models coupled to state-of-the-art fuel performance codes for each of the three main categories of phenomena considered as having high safety relevance for storage, namely helium behaviour, creep behaviour and hydrogen behaviour.

Operando high-speed X-ray radiography experiments reveal the cracking mechanism during 3D laser printing of a Ni superalloy.

In an exciting collaboration, Nick Phillips, a PSI Fellow at the cSAXS beamline, reveals nanoscale lattice distortions created by invisible defects in fusion reactor armor. This work develops the current understanding of how the smallest, but most prevalent defects, generated during neutron irradiation behave. The novel Bragg ptychographic approach published in Nature Communications paves the way for fast, robust, 3D Bragg ptychography.

Synchrotron X-ray diffraction experiments reveal the presence of a non- negligible amount of tetragonal phase in 3D printed red-gold samples. 

Magnetoelectric phenomena are intimately linked to relativistic effects and also require the material to break spatial inversion symmetry and time-reversal invariance. Magnetoelectric coupling can substantially affect light–matter interaction and lead to non-reciprocal light propagation. Here, we confirm on a fully experimental basis, without invoking either symmetry-based or material-specific assumptions, that the optical magnetoelectric effect in materials with non-parallel magnetization (M) and electric polarization (P) generates a trilinear term in the refractive index...

We report a new measurement of the n=2 Lamb shift in Muonium. Our result of 1047.2(2.3)_stat(1.1)_syst  MHz comprises an order of magnitude improvement upon the previous best measurement. This value matches ...