Future multifunctional hybrid devices might combine switchable molecules and 2D material-based devices. Spin-crossover compounds are of particular interest in this context since they exhibit bistability and memory effects at room temperature while responding to numerous external stimuli. Atomically thin 2D materials such as graphene attract a lot of attention for their fascinating electrical, optical, and mechanical properties, but also for their reliability for room-temperature operations. Here, we demonstrate that thermally induced spin-state switching of spin-crossover nanoparticle thin films can be monitored through the electrical transport properties of graphene lying underneath the films. Model calculations indicate that the charge carrier scattering mechanism in graphene is sensitive to the spin-state dependence of the relative dielectric constants of the spin-crossover nanoparticles. This graphene sensor approach can be applied to a wide class of (molecular) systems with tunable electronic polarizabilities.

@en

Scanning transmission electron microscopy (STEM) imaging is applied to analyze the electromigration-induced thickness variations of thin polycrystalline films. It is shown that a high angle annular dark field (HAADF) detector is required to minimize the effect of diffraction contact. A further reduction of the diffraction contrast can be obtained using a tilt series. A correlation between the intensity of the STEM signal obtained with the HAADF detector and the real thickness value was found by comparing corresponding STEM and AFM images. STEM in combination with a tilt series can determine the material distribution in polycrystalline films and can accurately analyze 1¿3 nm gaps of nanoelectrodes formed by electromigration@en

We investigated the reversible electromigration in Pd-Pt nanobridges by means of in situ electron microscopy. Real-time nanometer-scale imaging with scanning transmission electron microscopy was used to determine the material transport. For high current densities (3-5 x 10(7) A cm(-2)), material transport occurs from the cathode towards the anode side, indicating a negative effective charge. The electromigration is dominated by atom diffusion at grain boundaries on the free surface. The reversal of material transport upon a change of the electric field direction could be the basis of a memristor.@en