title: Structure-driven orientation of the high-spin-low-spin interface in a spin-crossover single crystal.
abstract: The orientation of the high-spin (HS)-low-spin (LS) macroscopic interface at the thermal transition of thin [{Fe(NCSe)(py)2}2(m-bpypz)] crystals is explained by considering the possible vanishing of the structural mismatch between the coexisting phases. The structural property which allows mismatch-free interfaces is characterized. The observed orientations of the interface and the tilt angle between the HS and LS domains are accurately reproduced by a two-dimensional continuous medium model, based on the structural data. Simulations using an atomistic electro-elastic model meet the predictions of the macroscopic analysis and provide information on the distribution of the elastic energy density in the biphasic state. The presence of mismatch-free domain structures can explain the exceptional resilience of these crystals upon repeated switching.
authors.affiliation: Groupe d'Etude de la Matière Condensée, Université de Versailles, CNRS UMR 8635, 45 Avenue des Etats-Unis, 78035 Versailles Cedex (France).
authors.forename: Mouhamadou
authors.initials: M
authors.lastname: Sy
authors.forename: François
authors.initials: F
authors.lastname: Varret
authors.forename: Kamel
authors.initials: K
authors.lastname: Boukheddaden
authors.forename: Guillaume
authors.initials: G
authors.lastname: Bouchez
authors.forename: Jérôme
authors.initials: J
authors.lastname: Marrot
authors.forename: Santoshi
authors.initials: S
authors.lastname: Kawata
authors.forename: Sumio
authors.initials: S
authors.lastname: Kaizaki
keywords: Monte Carlo simulations; elastic interfaces; optical microscopy; phase transitions; spin crossover