Unraveling the Environment Influence in Bistable Spin-Crossover Particles Using Magnetometric and Calorimetric First-Order Reverse Curves

Radu Tanasa (1) , Cristian Enachescu (1) , Jérôme Laisney (2) , Denis Morineau (3) , Alexandru Stancu (1) , Marie-Laure Boillot (2)

1 Universitatea Alexandru Ioan Cuza [Lasi]
2 ICMMO - Institut de Chimie Moléculaire et des Matériaux d'Orsay
3 IPR - Institut de Physique de Rennes

A first-order reversal curve (FORC) method is used here to analyze the unexpected change of memory characteristic of spin-crossover microparticles embedded in glass-forming or semicrystalline matrices, reflected in the larger hysteresis loop compared to the bulk. The huge reversibility shown by the reversal curves was attributed to the effect of the matrix, implying a variable external pressure and a cutoff–switch on mechanism of particle–matrix interactions. The FORC analysis indicates that heating and cooling processes in the case of matrix-embedded spin-crossover systems are driven by different mechanisms. In complement of standard magnetometry measurements, a calorimetry method, which demands an alternative method to extract FORC distributions, is introduced for tracking the signature of the composite transformation to understand and control the role of embedding matrices.

Domains: Chemical Sciences; Physics [physics]

Radu Tanasa, Cristian Enachescu, Jérôme Laisney, Denis Morineau, Alexandru Stancu, et al.. Unraveling the Environment Influence in Bistable Spin-Crossover Particles Using Magnetometric and Calorimetric First-Order Reverse Curves. Journal of Physical Chemistry C, 2019, 123 (15), pp.10120-10129. ⟨10.1021/acs.jpcc.9b00768⟩. ⟨hal-02143863⟩