Room‐Temperature Electrical Addressing of a Bistable Spin‐Crossover Molecular System

The design of switchable nanodevices based on magnetic molecules has therefore remained a theoretical topic. [ 10–12 ] Here, we report a switchable molecular device made by contacting individual nanoparticles based on spin-crossover molecules between nanometer-spaced electrodes. This nanoscale device exhibits switching and memory effects near room temperature as a consequence of the intrinsic bistability of the spin-crossover nanoparticle. Thus, a sharp increase in the conductance is observed upon heating above ca. 350 K, together with the presence of a thermal hysteresis as large as 30 K for a single-particle device, after which the conductance switches back to the original value. This is a long-sought-for result, as it confi rms the existence of hysteretic spin crossover effects in a single nanoobject. [ 13–17 ] Interestingly for molecular spintronics, the spin crossover in this molecular nanodevice can also be induced by applying a voltage, showing that its magnetic state is controllable electrically. Spin-crossover metal complexes are one of the paradigmatic examples of magnetic molecular materials showing switching and bistability at the molecular level. [ 18 ] In these systems lowspin to high-spin transitions can be triggered through a variety of external stimuli (temperature, illumination, or pressure) [ 19 ]