Issue
EPL
Volume 77, Number 3, February 2007
Article Number 30007
Number of page(s) 6
Section General
DOI http://dx.doi.org/10.1209/0295-5075/77/30007
Published online 01 February 2007
EPL, 77 (2007) 30007
DOI: 10.1209/0295-5075/77/30007

Light-induced phase separation in the $\chem{[Fe(ptz)_{6}] (BF_{4})_{2}}$ spin-crossover single crystal

F. Varret1, K. Boukheddaden1, C. Chong1, A. Goujon2, B. Gillon2, J. Jeftic3 and A. Hauser4

1  Groupe d'Etudes de la Matière Condensée (ex-LMOV), CNRS-Université de Versailles - 45 Avenue des Etats Unis F-78035 Versailles Cedex, France
2  Laboratoire Léon Brillouin (LLB), CEA-CNRS, CE Saclay - F-91191 Gif-sur-Yvette Cedex, France
3  Ecole Nationale Supérieure de Chimie de Rennes (ENSCR) UMR CNRS, 6052 - Av. du Général Leclerc Campus de Beaulieu, F-35700 Rennes, France
4  Département de Chimie Physique, Université de Genève - 30 quai Ernest-Ansermet, CH-1211 Geneva 4, Switzerland

francois.varret@uvsq.fr

received 18 July 2006; accepted in final form 11 December 2006; published February 2007
published online 1 February 2007

Abstract
We present novel insight on like-spin domains (LSD) in cooperative spin transition solids by following the photo-transformation and the subsequent relaxation of a [ Fe(ptz)6] (BF4)2 single crystal in the vicinity of the light-induced instability. Self-organization under light is observed, accompanied by Barkhausen-like noise and jumps which reveal the presence of elastic interactions between LSDs. The light-induced phase separation process is discussed in terms of a dynamic potential providing spinodal instability in the corresponding temperature range. This useful concept is applicable to all types of switchable molecular solids.

PACS
05.70.-a - Thermodynamics.
47.50.Gj - Instabilities.
64.75.+g - Solubility, segregation, and mixing; phase separation .

© Europhysics Letters Association 2007