Researchers from the Extreme Conditions Chemistry Laboratory (ECCL) at the Jožef Stefan Institute (Matic Belak Vivod, Matic Lozinšek, and Mirela Dragomir) along with their collaborators (Zvonko Jagličić, Graham King, Thomas C. Hansen), have introduced mechanochemistry as a novel method for synthesizing reactive silver(II) compounds. This innovative approach allowed them to prepare the first examples of binary mixed-valent silver(I,II) fluorides, Ag₃F₄ and Ag₂F₃. The crystal structures of these new compounds were determined using powder X-ray diffraction measurements at the Canadian Light Source (CLS) synchrotron. Magnetic measurements, along with neutron powder diffraction (NPD) data from the Institut Laue-Langevin (ILL), revealed that these binary silver(I,II) fluorides exhibit low dimensional (1D) antiferromagnetic behavior. These compelling results suggest that mechanochemical synthesis can expand the silver(II) chemistry, potentially enabling the preparation of other mixed-valent phases and compounds of transition metals in rare oxidation states. This study, published in the Journal of the American Chemical Society, is dedicated to the memory of Professor Dr. Boris Žemva. |
Prof. Ingrid Milošev, the Head of the Department of Physical and Organic Chemistry at the Jožef Stefan Institute and Full Professor at the Jožef Stefan International Postgraduate School, is this year's recepient of the prestigious international award H.H. The Uhlig Award, awarded by the learned society The Electrochemical Society based in the USA. The Award, which was awarded in 1973 in memory of this outstanding scientist in the field of corrosion, was given to Prof. Milošev for outstanding achievements in corrosion science and technology with fundamental contributions to corrosion inhibition research, surface treatment and corrosion of biomaterials. Her research focuses on corrosion processes and corrosion protection of technological and biomedical materials, including corrosion inhibitors, sol-gel coatings, conversion and inorganic coatings. Dr. Milošev has published 240 articles in peer-reviewed journals and nine book chapters with more than 13,300 citations (h-index 58). At the awarding ceremony, Prof. Milošev gave an invited lecture entitled "The Remarkable Versatility of Copper: From its Corrosion Resistance to Antibacterial Properties". |
Researchers from F3 and F7 Departments of the Jožef Stefan Institute in collaboration with researchers from the Faculty of Mechanical Engineering, University of Ljubljana and Coimbra University (Portugal) investigated in the picosecond excitation regime the photoacoustic (PA) response of composite material made of graphene or graphene decorated with gold nanoparticles (AuNP) and polydimethylsiloxane (PDMS). AuNP attached to graphene improve the dispersibility of the flakes in the polymer, increase the surface area in contact with the polymer, and prevent the re-adhesion. All of this leads to a better intercalation of the polymer with the graphene flakes and a more uniform and efficient generation of PA waves. By using picosecond excitation of the graphene-based composite, we measured PA waves with bandwidths of 70 MHz and 130 MHz at -6 dB and -20 dB. The peak pressures of the PA waves achieve values > 5 MPa. The bandwidth can be further increased to values of 85 MHz at -6 dB and 135 MHz at -20 dB by decorating the graphene with AuNP. The results of the research were published in the journal Nano Energy and EU patent was granted. |
Feynman diagrams are an important tool in modern theoretical physics, with applications in solid-state, high-energy physics, and quantum chemistry. Doc. dr. Denis Golež from the Department of Theoretical Physics and his colleagues from the Flatiron Institute (USA), Berkeley University (USA) and the University of Örebro (Sweden) discovered a new approach for using Feynman diagrams in quantum materials, published in Physical Review X. Higher-order Feynman diagrams are challenging in strongly correlated quantum systems due to their computational complexity. This study uncovered a 'hidden structure' within these high-order diagrams based on the separability of quantum propagators, see figure, significantly reducing computational demands. The algorithm was applied to non-perturbative problems where traditional quantum Monte Carlo methods would fail, offering a promising new tool for diagrammatic computations. This theoretical advancement is expected to greatly facilitate the discovery of new quantum collective states, such as excitonic magnetism and spin glasses. |
