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Marta Lavrič, in collaboration with a group from Department of Complex Matter F7 (A. Sterle, P. Medle Rupnik, L. Cmok, A. Erkoreka, N. Osterman, A. Mertelj, N. Sebastián) and research groups from University of Leeds (C. J. Gibb, J. Hobbs, R. J. Mandle) and University of the Basque Country (A. Erkoreka, J. Martinez-Perdiguero), has published an article entitled “Elasticity-Driven Periodic Polarization Patterns in a Chiral Ferroelectric Nematic Fluid” in Advanced Materials.

The interplay between chirality, confinement and elasticity can drive the spontaneous formation of complex polarization patterns in chiral ferroelectric nematic liquid crystals. These three factors work together to transform an initially uniform state into a variety of ordered structures.

In a new study the researchers show that when the pitch of the material under confinement deviates from its natural pitch, periodic instabilities emerge as the material approaches a heliconical polar state. Near such transition, the bend elastic constant of the liquid crystal softens. The combination of the material’s preferred helical structure, confinement and reduced resistance to bending drives the formation of periodic polarization patterns.

Under confinement, these instabilities give rise to a variety of self-organized structures, including stripes, squares and hexagonal patterns. By changing the thickness of the confined material and the surface alignment, the researchers can control which structures emerge.… Read the rest “Elasticity-Driven Periodic Polarization Patterns in a Chiral Ferroelectric Nematic Fluid”

Marta Lavrič in George Cordoyiannis sta v sodelovanju s sodelavci z odseka Kompleksne snovi (A. Sterle, N. Sebastian in A. Mertlej) ter skupinami iz Češke akademije znanosti (N. Podoliak, M. Cigl, P. Golub, V. Novotna) in Univerze v Baskiji (A. Erkoreka, J. Martinez-Perdiguero) objavila članek z naslovom »The effect of side chain length on the mesomorphic properties of ferroelectric nematogens (Efekt dolžine stranske verige na mezomorfne lastnosti feroelektričnega nematika)« v reviji Materials Advances.

V članku je bil spremenjen in raziskan predhodno opisan feroelektrični nematogen, ki temelji na molekulski strukturi z dimetilamino zaključno skupino. Raziskan je bil vpliv njegove dolžine na mezomorfne lastnosti v dveh novih homologih s podaljšano stransko verigo. Medtem ko imajo prej opisani homologi neposreden prehod iz izotropne faze (Iso) v feroelektrično nematsko fazo (NF), se pri podaljšani alkilni verigi pojavi ozka vmesna nematska faza (N).

Za nove spojine so bile določene njihove mezomorfne in materialne lastnosti. Feroelektričnost NF faze je bila potrjena z merjenjem polarizacije, SHG signala in permitivnosti.

DOI: 10.1039/d6ma00897f

Marta Lavrič je v sodelovanju s skupino iz Prage (M. Cigl, N. Podoliak, D. Repček, P. Golub in V. Novotna) objavila članek z naslovom »The effect of fluorine or chlorine substitution on mesomorphic properties of ferroelectric nematic liquid crystals (Efekt fluorove in klorove zamenjave na mezomorfne lastnosti feroelektričnega nematskega tekočega kristala)« v reviji Materials Advances.

Feroelektrična nematska faza (NF) predstavlja zelo zanimivo in hitro razvijajoče se področje raziskav tekočih kristalov, ki združuje fluidnost s feroelektričnostjo. Materiali z NF fazo izkazujejo velike vrednosti polarizacije in izjemne nelinearne optične lastnosti. V članku so bile izdelane izvirne molekulske strukture, tako brez substituentov, kot tudi s halogenskimi substituenti na mestu electron-donorske skupine. Pri tem je treba upoštevati, da uporaba atoma klora (Cl) pri načrtovanju feroelektričnih nematogenov še ni bila predhodno opisana. Pri homologih z razširjenim molekulskim jedrom je bila med ohlajanjem pod nematsko fazo opažena feroelektrična nematsko faza. Poleg tega smo pri nesubstituiranem homologu ugotovili, da je NF enantiotropna v širokem temperaturnem območju. Predstavljeni rezultati zagotavljajo dragocen vpogled v molekulsko načrtovanje feroelektričnih tekočekristalnih spojin.

DOI: 10.1039/D6MA00129G

Asst. Prof. Matjaž Gomilšek from the from the Condensed Matter Physics Department F5 at the Jožef Stefan Institute and the Faculty of Mathematics and Physics, University of Ljubljana has recently been elected to represent the magnetism community of Slovenia in the General Council (GC) of the European Magnetism Association (EMA) for a three-year term.
EMA is a non-profit organisation promoting the development of magnetism and magnetic materials in Europe by raising the visibility and impact of research on fundamental and applied magnetism.
The GC consists of representatives of the European countries active in magnetism research and defines the general policy of EMA, overseeing key activities such as the Joint European Magnetic Symposia (JEMS) conference and the European School on Magnetism (ESM).
Members of Slovenia’s magnetism community are warmly encouraged to reach out to Asst. Prof. Matjaž Gomilšek to share ideas, raise topics of interest, or explore opportunities to get involved in EMA activities (for additional information, see magnetism.eu).

Researchers from the Jožef Stefan Institute and the Faculty of Mathematics and Physics, University of Ljubljana, together with collaborators from Japan, the USA, and Greece, have reported the discovery of a robust metallic state in the molecular material Yb2CsC60. The study has been published in Nature Communications.

The work explores how strong electronic correlations behave in fullerene-based molecular solids containing a single “hole” in multiorbital electronic states. Using synchrotron X-ray diffraction, neutron scattering, Raman spectroscopy, NMR, X-ray absorption spectroscopy, and first-principles calculations, the team demonstrated that Yb2CsC60 remains metallic without undergoing a Mott transition.

The results reveal a remarkable analogy between correlated molecular p-electron systems and transition-metal d-electron materials, providing new insight into Hund-coupling physics and strongly correlated quantum matter. The newly synthesized orthorhombic fulleride may also open pathways toward discovering unconventional superconductivity in related molecular systems.

The paper:
“Survival of the metallic state in a single-hole multiband p-orbital molecular system”
K. Matsui, R. A. Klein, N. Yoshikane, J. Arvanitidis, M. Gomilšek, U. Klopčič, S. Kawaguchi, H. Yamaoka, N. Hiraoka, H. Ishii, Q. Zhang, S. Mori, H. Ishibashi, Y. Kubota, Craig M. Brown, Denis Arčon, and Kosmas Prassides. Nature Communications 2026.