doi:10.1002/advs.202508262engKerschbaumer, SamuelOndrácek, MartinHadjadj, Sebastien E.Stetsovych, OleksandrPinar Solé, AndrésCandia, Adriana ElizabetAngulo-Portugal, PaulaAguirre-Baños, AndreaCorso, MartinaSerrate, DavidLobo-Checa, JorgeJelínek, PavelIlyn, MaximPiaggi, Pablo M.Rogero, CeliaCoverage-Dependent Structural Evolution of CoBr2 at the Au(111) InterfaceART-2025-146330Unraveling the growth mechanism of van der Waals materials is crucial for their device implementation, as this improves the overall film quality, allowing precise control of their electronic and magnetic properties in nanoscale applications. The initial structure formed on the substrate during growth is often assumed to be bulk-like, thereby neglecting the role of the surface in the assembly. Here, the coverage–dependent growth of CoBr2 on Au(111) from a stoichiometric molecular powder is studied using a combination of experimental techniques, machine–learning-driven molecular dynamics simulations and density functional theory calculations. It is found that CoBr2 molecules initially form a molecular precursor phase characterized by three-molecule clusters arranged in a surface–stabilized structure with long-range order and a periodic coincidence with Au(111). As the surface coverage is increased, this phase subsequently undergoes a transition to form the equilibrium van der Waals crystal layered structure observed for the bulk material. These findings challenge conventional views of direct van der Waals layer formation and provide new insight into the role of the substrate during the growth process.2025http://zaguan.unizar.es/record/16415910.1002/advs.202508262http://zaguan.unizar.es/record/164159oai:zaguan.unizar.es:164159info:eu-repo/grantAgreement/ES/DGA/E12-23Rinfo:eu-repo/grantAgreement/EC/H2020/101064332/EU/Addressing molecular spin qubits by ESR-STM/QMOLESRThis project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No H2020 101064332-QMOLESRinfo:eu-repo/grantAgreement/ES/MCIU/PID2020-114252GB-I00info:eu-repo/grantAgreement/EUR/MCIU/TED2021-130292B-C42info:eu-repo/grantAgreement/EUR/MCIU/TED2021-132388B-C43info:eu-repo/grantAgreement/ES/MICINN AEI/PID2022-138750NB-C21info:eu-repo/grantAgreement/ES/MICINN AEI/PID2022-138750NB-C22info:eu-repo/grantAgreement/ES/MCINN/PID2022-140845OB-C65info:eu-repo/grantAgreement/ES/MCIU/PID2023-148225NB-C31Advanced Science (2025), e08262 [8 p.]byhttps://creativecommons.org/licenses/by/4.0/deed.esinfo:eu-repo/semantics/openAccess