News

Ursula Keller wins “Swiss Nobel” Marcel Benoist Prize- for pioneering work in ultrafast lasers

Farewell: the NCCR MUST ended - on June 30, 2022

MUST2022 Conference- a great success!

New scientific highlights- by MUST PIs Wörner, Chergui, and Richardson

FELs of Europe prize for Jeremy Rouxel- “Development or innovative use of advanced instrumentation in the field of FELs”

Ruth Signorell wins Doron prizefor pioneering contributions to the field of fundamental aerosol science

New FAST-Fellow Uwe Thumm at ETH- lectures on Topics in Femto- and Attosecond Science

International Day of Women and Girls in Science- SSPh asked female scientists about their experiences

New scientific highlight- by MUST PIs Milne, Standfuss and Schertler

EU XFEL Young Scientist Award for Camila Bacellar,beamline scientist and group leader of the Alvra endstation at SwissFEL

Prizes for Giulia Mancini and Rebeca Gomez CastilloICO/IUPAP Young Scientist Prize in Optics & Ernst Haber 2021

Nobel Prize in Chemistry awarded to RESOLV Member Benjamin List- for the development of asymmetric organocatalysis

Hans Jakob Wörner invited to give the „New Horizons Solvay Lectures” - online, October 5, 12 and 19

Unusual keynote talk at an international scientific conference- Do photons show gender bias?

NCCR MUST at Scientifica 2021- Lightning, organic solar cells, and virtual molecules

Ultrafast Transient Increase of Oxygen Octahedral Rotations in a Perovskite

August 9, 2019 (more to follow)

Via femtosecond hard x-ray diffraction we identified a perovskite system that complements the rare selection of materials in which a symmetry broken phase can be transiently stabilized by photoexcitation. EuTiO3 exhibits a second order purely structural phase transition (TC = 290 K) which is characterized by an antiferrodistortive rotation of the oxygen octahedra (see figure, left unit cell) with the rotation angle being the order parameter. We directly monitor this angle upon photoexcitation across the band gap (data points) via x-ray pulses obtained from a FEL. Within the first few-hundred femtoseconds after excitation we observe a transient increase of rotation angle. This stands in contrast to the situation of an increased temperature for which the order parameter decreases. We ascribe the surprising increase of the order parameter to a transient effective change of ionic sizes that transforms directly into an ultrafast change of the Goldschmidt tolerance factor. The ability to modify the Goldschmidt tolerance factor provides another tuning parameter to control electronic and magnetic properties of perovskites on ultrafast timescales.

Reference: M. Porer, M. Fechner, M. Kubli, M.J. Neugebauer, S. Parchenko, V. Espositio, A. Narayan, N. A. Spaldin, R. Huber, M. Radovic, E. M. Bothschafter, J. M. Glownia, T. Sato, S. Song, S. L. Johnson, and U. Staub.
Phys. Rev. Research 1. 012005 (R) (2019). DOI: 10.1103/PhysRevResearch.1.01005