Addressing single spin crossover molecules in a two-dimensional monolayer

Abstract Bistable spin-crossover molecules are particularly interesting to the development of innovative electronic and spintronic devices as they present two spin states that can be controlled by external stimuli. In this purpose, being able to switch at will the spin state of a single molecule in a dense molecular array is a key milestone. However, the elastic interactions between the molecules favour more cooperative behaviour where patches of neighbouring molecules switches simultaneously. We demonstrate here that the interaction of iron II spin-crossover molecules with a metallic substrate can strongly reduce their cooperative behaviour until addressing independently single molecular spin state. Mechanoelastic model is able to reproduce well such findings.