Photocontrol of the Magnetic Response of Molecular Magnets at Interfaces

University Of Florida, Gainesville FL

Investigators

Abstract

Non-Technical Abstract: Polymer-like molecular networks are softer than common solid-state materials. When a molecular magnet is chemically attached to a photoactive molecular network, changes of temperature and irradiation by light generate strains on the magnetic domains near the interface. This single investigator award allows for the study of these processes in new, nano-scaled environments that are not available in macroscopic crystals. The results provide a basis for exploring light-controlled, magnetic devices for new applications in spintronics. The research is interdisciplinary and international in scope, and junior researchers, comprised of undergraduate and graduate students, are trained in a wide-range of experimental, theoretical, and computational skills while working with a diverse team. An international team in Slovakia is intimately involved in the experiments, and this productive collaboration provides scientific and cultural exposure for everyone. Organized outreach activities focus on K-8 students and teachers, and hands-on activities are designed to enhance the science content knowledge of all participants. Technical Abstract: The properties of molecule-based magnets can be tuned by synthesis protocols and controlled by external stimuli such as temperature, electric/magnetic fields, pressure/strain, and irradiation by light. One goal of this single investigator research is to investigate the mechanisms governing the photocontrol of the magnetic response of nano-sized heterostructures of coordination polymers, where one magnetic component is mated to a photo-active constituent. Spin-polarized small-angle neutron scattering (SANS) techniques are well-suited to detect and measure the changes of the magnetic profiles at and near the interface between the two components of these heterostructured nanoparticles. Another goal is to shift the photoactive states of spin-crossover complexes placed in nano-textured, metastable morphologies. By restricting the molecules to a nanophase environment and tuning the influence of the substrate, the cooperativity of the nano-scaled domains is modified to allow photo-switching at higher temperatures. Scanning tunneling spectroscopy is the main tool for these surface studies, and the experimental results are interactively shared with an in-house computational team that is focused on the in-silico design of new materials. The results directly impact future investigations to define photo-switchable nano-scaled molecular arrangements suitable for spintronic applications.