The winner of the Erwin Felix Levi Bertaut prize 2026 is Dr. Laura Guasco
The European Crystallographic Association (ECA) and the European Neutron Scattering Association (ENSA) have jointly announced Dr. Laura Guasco, a member of the Solid State Spectroscopy Department, as the winner of the Erwin Félix Lewy Bertaut Prize 2026.
Laura Guasco demonstrated several elegant and highly original applications of spin-polarized neutron reflectometry to thin-film structures of current interest, taking particular advantage of the sensitivity of this method to hydrogen in solids. In particular, she recognized the potential of neutron waveguide resonances for hydrogen detection and quantification in solids and developed a new “resonant neutron reflectometry” method that enhances the sensitivity of neutron reflectometry by about an order of magnitude (Guasco et al., Nature Communications 13, 1486 (2022)).
Her method greatly facilitates the determination of the absolute hydrogen content, which is directly encoded in the momentum-space position of the waveguide resonance and therefore does not require any modelling. Laura Guasco further showed that the method allows in situ measurements of hydrogen content and electronic transport properties in real time.
In a kinetic study of hydrogen in niobium films, she found interesting differences between the time evolution of the neutron waveguide resonance, the lattice parameters measured by X-ray diffraction, and the electrical transport properties – all measured in situ at the same time. Based on a detailed analysis of these multiple data sets, she developed a model for the sequential incorporation of hydrogen into microcracks and interstitial sites (Guasco et al., Advanced Functional Materials, e75202 (2026)). The resulting insights into the mechanisms of hydrogen incorporation in materials are likely to become increasingly relevant as visions of a “hydrogen economy” move closer to reality.
Together with Rebecca Pons and other members of the Solid State Spectroscopy Department, Laura Guasco also used neutron reflectometry and complementary probes to investigate the influence of hydrogen incorporation on the structure and electronic properties of metal-oxide thin-film systems. In particular, she recently observed a highly unusual re-entrant metal-insulator transition driven by hydrogen incorporation in nickelate films.
An elegant analysis scheme allowed her to determine the origin of this observation by independently extracting the hydrogen and oxygen stoichiometry from the neutron data and the Ni valence state from complementary X-ray absorption measurements (Guasco, Pons et al., Advanced Functional Materials 35, 2419253 (2025)). The results illustrate the potential of resonant and non-resonant neutron reflectometry for research into hydrogen effects in electronic materials and devices.
