  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.
