Phase-transitions in spin-crossover thin films probed by graphene transport measurements

TL;DR

This study demonstrates that the spin-state switching of spin-crossover nanoparticle thin films can be detected via electrical transport measurements in graphene, enabling potential applications in hybrid molecular-2D material devices.

Contribution

It introduces a graphene-based sensor method to monitor spin-crossover transitions through electrical transport, linking dielectric changes to charge carrier scattering.

Findings

Graphene's electrical properties are sensitive to spin-state changes in underlying nanoparticles.

Spin-crossover transitions influence the dielectric environment, affecting graphene conductivity.

The approach is applicable to various molecular systems with tunable polarizabilities.

Abstract

Future multi-functional 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.