We use the electrode-less time-resolved microwave conductivity (TRMC) technique to characterize spin-crossover (SCO) nanoparticles. We show that TRMC is a simple and accurate mean for simultaneously as-sessing the magnetic state of SCO compounds and charge transport information on the nanometre length scale. In the low-spin state from liquid nitrogen temperature up to 360 K the TRMC measurements present two well-defined regimes in the mobility and in the half-life times, possessing similar transition tempera-tures TR near 225 K. Below TR, an activation-less regime associated with short lifetimes of the charge carri-ers points at the presence of shallow-trap states. Above TR, these states are thermally released yielding a thermally activated hopping regime where longer hops increases the mobility and, concomitantly, the barrier energy. The activation energy could originate from intricate contributions such as polaronic self-localizations, but also from dynamic disorder due to phonons and/or thermal fluctuations of SCO moieties.
@article{arxiv.1803.01073,
title = {Charge Mobility and Dynamics in Spin-crossover Nanoparticles studied by Time-Resolved Microwave Conductivity},
author = {Julien Dugay and Wiel Evers and Ramón Torres-Cavanillas and Mónica Giménez-Marqués and Eugenio Coronado and Herre S. J. Van der Zant},
journal= {arXiv preprint arXiv:1803.01073},
year = {2018}
}