Fermer le menu


Heteroepitaxial interfaces coupling photo- and magnetostrictive properties based
on charge-transfer solids

Photostrictive and shape responsive solids constitute an important class of functional materials with applications in micro-actuation and sensing, energy harvesting or photonics. They offer new opportunities in non-contact and wireless technologies, such as remote control and decreased sensitivity to electromagnetic interferences. For instance, spin-crossover and charge-transfer molecular solids exhibit elongations under illumination that can reach 3.4% along specific crystallographic directions. This photostriction has been be exploited to optically control magnetic properties through an inverse magnetostriction effect both in multilayer and core-shell architectures. This presentation will give an overview of our recent studies aimed at identifying the main levers to increase this mechanical coupling in core-shell particles, using basic concepts of classical nucleation theory to selectively control either the core or the shell microstructure. In-situ x-ray powder diffraction and x-ray absorption spectroscopy experiments were combined to determine the local strain field, the time response of the structural changes and address specific questions such as the impact of (i) the volume ratio between the two compounds, (ii) an adaptive lattice matching across the interface or (iii) interface roughness.

Isabelle Maurin
Laboratoire de Physique de la Matière Condensée, Ecole polytechnique, Palaiseau
actuellement en mission à ESRF/Institut Néel (équipe MRS)