Notizie

Coking is the central source of deactivation of zeolite catalysts. Using in situ XPS along with complementary methods, we identify differences in the formation kinetics and composition of surface coke on industrially relevant ZSM-5 catalysts during MTH conversion, demonstrating the strong potential of this technique for studying catalyst deactivation due to coking.

A team of scientists, led by researchers at PSI, has introduced the Materials Cloud Three-Dimensional Structure Database (MC3D), a systematically curated database of quantum-mechanical calculations for inorganic materials derived from experimental crystal structures. The database contains more than 32 000 structures whose relaxed geometry and electronic structure were computed using carefully standardized DFT workflows, using three different functionals and/or computational protocols. Beyond providing a consistent reference dataset for computational materials science, MC3D also supports emerging data-driven approaches. For example, it served as a starting point for datasets used to train machine-learning interatomic potentials.

Transition metals exemplify correlated electronic systems, where electron-electron (𝑒−𝑒) scattering often results in a quadratic temperature dependence of the electrical resistivity, 𝜌⁡(𝑇) ∝𝑇2. In SrVO3 (SVO), a material with a 𝑉−3⁢d1 electronic configuration that ensures metallicity through narrow 3⁢𝑑−t2⁢𝑔 bands, a 𝜌⁡(𝑇) ∝𝑇2 dependence has been reported. While traditionally attributed to 𝑒−𝑒 scattering, recent studies suggest that electron-phonon (𝑒-ph) interactions may play a significant role. To unravel the influence of phonon interactions on carrier transport in SVO, we present a comparative study of the transport and optical properties of SVO films with partial substitution of 16O ions by their heavier isotope, 18O. Our findings reveal that 18O substitution induces a change in the slope of 𝑑⁢𝜌⁡(𝑇)/𝑑⁢𝑇 at nominal fixed carrier density, highlighting the dominant contribution of 𝑒-ph coupling over 𝑒−𝑒 scattering in determining 𝜌⁡(𝑇). Furthermore, it is found that the 18O substitution softens the phonon lattice and promotes a reduction in plasma frequency and an increase in the carrier effective mass. These results indicate that the 𝑒-ph coupling strength increases upon 18O substitution. Our findings suggest that 𝑒-ph interactions may surpass 𝑒−𝑒 scattering in governing the resistivity of metallic ionic lattices. ...

Powerful atomistic simulation tools have transformed materials research, but their complexity still limits who can use them and how easily results can be reproduced: a gap that a new web-based app now helps close. The AiiDAlab Quantum ESPRESSO app, described in a recent publication in npj Computational Materials, can run not only isolated calculations but also complete, end-to-end computational workflows involving multiple passages over several different materials, lowering the barrier for both experimentalists and computational experts. This is achieved through the tight integration of the widely-used Quantum ESPRESSO simulation software package with the AiiDA engine, a workflow-management system to help automate complex simulations in materials science (whose development is led by the Materials Software and Data group at PSI), which has provided substantial support to its development alongside contributions from the broader community.

ISS received the first light on 10.07.2025. After that, the endstation has been reconnected and aligned. During the shutdown period, the ScientaOmicron R4000 HiPP-2 analyser has undergone maintenance and upgrade. It features now a new detector (new MCP and 70 Hz camera) and ethernet communication.

First in-house and pilot users have measured in November and December 2025. A first official call for proposals will open in February 2026 (deadline March 16^th 2026, beamtime periods scheduled from September to December 2026). Please contact Dr. Luca Artiglia for more information.  

Resonant inelastic x-ray scattering reveals that lattice vibrations can be chiral in a polar material, with phonons having opposite handedness depending on their direction in momentum space.

Across the fields of magnetism, microelectronics, optics, and others, engineered local variations in material properties can yield groundbreaking functionalities that play a crucial role in enabling future technologies. One-dimensional lateral gradients in material properties give rise to a plethora of new effects in thin-film magnetic systems. However, extending such gradient-induced behaviors to two dimensions has been challenging to realize experimentally. Here, we demonstrate the creation of two-dimensional complex patterns with continuous variations in magnetic anisotropy, interlayer exchange coupling, and ferrimagnetic compensation at the mesoscopic scale in numerous application-relevant magnetic materials. We exploit our engineered gradients in material properties to demonstrate novel magnetic functionalities, including the creation of a spin wave band pass filter and an architecture for passively resetting the position of a magnetic domain wall. Our results highlight the exciting new physics and device applications enabled by two-dimensional gradients in thin film properties.

We quantify “how chiral” a crystal is, and demonstrate its tunability at ultrafast timescales. This achievement does open up a new direction in chirality-related condensed matter physics and on emergent phenomena, which have both attracted significant attention recently.

The 2D self-arrangement of a molecule that resembles three-armed spirals leads to a triangular pattern that is effectively aperiodic.

By combining in situ XPS measurements carried out at ISS with theoretical calculations, reactivity/kinetics tests and high resolution electron microscopy, it was demonstrated that the reactivity of a Pt/CeO₂ towards the low temperature water gas shift reaction is boosted on small platinum clusters originated by sintering of atomically dispersed species. A comprehensive model allowed to determine the most active sites, which are corner sites at the perimeter between platinum and ceria. 

X-ray magnetic circular dichroism (XMCD) is a magneto-optical effect that describes the difference in absorption between left and right circularly polarized X-rays by a magnetized material. It has been widely applied to the study of magnetic systems and of magnetic phenomena and its unique capabilities make it a fundamental tool for the study of novel magnetic phenomena and new materials systems.

Transmission electron and soft x-ray microscopy have contributed significantly to our understanding of phenomena in fields ranging from biology to materials science. In this review, we present recent developments in combining transmission electron and soft x-ray microscopy techniques, including progress in sample environment, and in situ and operando approaches and highlight the unique opportunities offered by fully correlative transmission electron and soft x-ray microscopy.

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.