Eur. Phys. J. B 6, 183-193 (1998)
https://doi.org/10.1007/s100510050540

Light-induced bistability in spin transition solids leading to thermal and optical hysteresis

¹ Laboratoire de Magnétisme et d'Optique, CNRS-Université de Versailles, 45 avenue des États-Unis, 78035 Versailles Cedex, France
² Institut de Recherche sur la Réactivité, l'Électrochimie et la Microporosité, CNRS-Université de Versailles, 45 avenue des États-Unis, 78035 Versailles Cedex, France
³ Leiden Institute of Chemistry, Gorlaeus Laboratories, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands

Corresponding author: ^a fvarret@physique.uvsq.fr

Received: 5 June 1997
Accepted: 17 July 1998
Published online: 15 November 1998

Abstract

We investigate the behaviour of photo-excitable, bistable systems, under permanent light irradiation, in presence of relaxation towards the non-excited state. Cooperativity causes bistability of the steady state, leading to light-induced thermal and optical hysteresis (LITH and LIOH). The light-induced instability is expected to induce demixtion, i.e. the coexistence of domains of the two stable steady states. Such effects are evidenced by magnetic and reflectivity measurements on the spin-crossover solid solution: , with x= 0.3, 0.5, 0.85. Experimental data are in quantitative agreement with a simple macroscopic model which includes a non-linear relaxation term in the master equation.