BEGIN:VCALENDAR
PRODID:-//Events Calendar//iCal4j 1.0//EN
METHOD:PUBLISH
VERSION:2.0
BEGIN:VEVENT
DTSTAMP:20260813T031442Z
DTSTART:20260421T140000
DTEND:20260421T150000
SUMMARY:Formation of Europium-transition metal surface compounds and protection of Eu below hexagonal boron nitride (h-BN)
UID:20260813T031442Z-uidGen@ovm-jahia-app1.esrf.fr
DESCRIPTION:In this work\, the formation and protection of two-dimensional (2D) ferromagnetic surface alloys are achieved by intercalating europium (Eu) beneath a protective monolayer of hexagonal boron nitride (h-BN) on various transition metal (TM) substrates. Low energy electron diffraction (LEED)\, scanning tunnelling microscopy (STM)\, x-ray photoelectron spectroscopy (XPS)\, angle-resolved photoemission spectroscopy (ARPES)\, and x-ray magnetic circular dichroism (XMCD) were employed to study structural\, electronic\, and magnetic properties across both flat and curved (vicinal) surfaces including c-Pt(111)\,  Rh(111)    and      c-Ni(111). The structural characterisation of h-BN grown on flat and curved TM substrates revealed that substrate crystallographic orientation and lattice mismatch critically influence h-BN growth with insights supported by DFT calculations. h-BN growth was found to induce faceting in all studied systems. For strongly interacting systems\, only a few stable facets were observed\, such as in the h-BN/c-Ni(111) system\, while weakly interacting systems exhibited more stable facets\, exemplified by the h-BN/c-Pt(331) system. The latter was further explored through DFT to understand the mechanism of stable facet formation. Furthermore\, Eu intercalation below h-BN on Pt(111) and on Rh(111)\, led to the formation of ordered EuPt2 and EuRh2 surface alloys\, respectively\, which are protected by h-BN. Their formation confirmed by (√3 × √3)R30◦ superstructure observed in the LEED\, predominantly divalent Eu signal in Eu 3d core level XPS spectrum\, and ferromagnetic ordering with Curie temperature of 14.1 K for EuRh2 as demonstrated by XMCD. h-BN provided partial oxidation protection in all systems\, especially in c-Pt(111) at (111) and\, surprisingly\, in c-Ni(111) away from (111).
LOCATION:Room 018\, Central Building
CATEGORIES:Seminar
LAST-MODIFIED:20260413T133212Z
CONTACT:Experiment Division Assistants\, +33 (0)4 38 88 19 92\, expdiv-sec@esrf.fr
URL:https://www.esrf.fr/cms/live/live/fr/sites/www/home/events/Seminars/area-events/esrf-seminars-list/formation-of-europium-transition-metal-surface-compounds-and-protection-of-eu-below-hexagonal-boron.html
CLASS:PUBLIC
END:VEVENT
END:VCALENDAR