Impact of single crystal properties on nucleation and growth mechanisms of a spin transition

We have investigated the spatio-temporal development of the spin transition in different single crystals of the molecular complex [Fe(bapbpy)(NCS)2] using optical microscopy. The thermal spin transition proceeds by nucleation at macroscopic defects, followed in most cases by anisotropic growth. We show that a lower crystalline quality leads to multi-site nucleation and intermittent spin transitions. We conclude that each crystal of a same spin crossover complex can have its proper spin transition kinetics depending on its crystalline properties and intrinsic microstructure.

Graphical abstractWe compared the spatio-temporal dynamics of the spin transition in different single crystals of a same spin crossover complex. Optical microscopy revealed that each crystal can have its proper spin transition kinetics dependent on its crystalline properties and intrinsic microstructure.Figure optionsDownload full-size imageDownload as PowerPoint slide