title: Electronic and structural aspects of spin transitions observed by optical microscopy. The case of [Fe(ptz)6](BF4)2.
abstract: The colorimetric analysis of images recorded with an optical microscope during the onset of the spin crossover transformation allows monitoring separately the involved electronic and structural aspects, through the separation of resonant absorption and scattering effects. Complementary information can also be obtained by using the polarized modes of the microscope. These potentialities are illustrated by the observation of [Fe(ptz)(6)](BF(4))(2) single crystals during the onset of the thermal transitions in the 110-140 K range. We characterized the interplay between the electronic (HS <--> LS) and structural (order <--> disorder) transformations. Elastic stresses and mechanical effects (hopping, self-cleavage) generated by the volume change upon electronic transition are also illustrated, with their impact on the photoswitching properties of the crystals.
authors.affiliation: Groupe d'Etude de la Matière Condensée, CNRS-Université de Versailles UMR 8635, 45 avenue des Etats-Unis, 78035 Versailles cedex, France.
authors.forename: Christian
authors.initials: C
authors.lastname: Chong
authors.forename: Haritosh
authors.initials: H
authors.lastname: Mishra
authors.forename: Kamel
authors.initials: K
authors.lastname: Boukheddaden
authors.forename: Stéphane
authors.initials: S
authors.lastname: Denise
authors.forename: Guillaume
authors.initials: G
authors.lastname: Bouchez
authors.forename: Eric
authors.initials: E
authors.lastname: Collet
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Ameline
authors.forename: Anil D
authors.initials: AD
authors.lastname: Naik
authors.forename: Yann
authors.initials: Y
authors.lastname: Garcia
authors.forename: François
authors.initials: F
authors.lastname: Varret