Magnetoelastic modeling of core-shell spin-crossover nanocomposites

Abstract

Spin-crossover (SCO) solids have been studied from magnetic and structural viewpoints under the form of powder, single crystals, and nanoparticles. Recently, an important progress made in chemistry allowed the design of spin-crossover nanocomposites, combining the properties of two types of spin-crossover solids having different properties, for example, different transition temperatures, ligand fields, etc. In this work, we sketch theoretical investigations based on an elastic description of a SCO nanocomposite, aiming to reproduce the experimental results of literature which exhibited two-step and even three-step spin transitions. Our results not only reproduce the experimental features but also allow a better understanding of the interplay between the elastic and electronic structures of the two components of the SCO nanocomposite. The obtained data offer serious possibilities of extensions to several configurations of nanocomposites according to the shape of the lattice and the relative sizes of the two components under study.

Molecular Spin Crossover Materials: Review of the Lattice Dynamical Properties

“…Experiments and simulations also revealed a significant matrix effect both on the vibrational spectra and on the SCO properties of particles. Indeed, compressive or tensile stress exerted by the matrix on the particles may lead to a modification of the internal pressure . Consequently, the HS‐LS phase stability as well as the cooperativity of the SCO are impacted.…”

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

“…Spin-crossover nano- or microparticles were generally used as coated with stabilizers or dispersed in various media (surfactants, polymers, and glass-forming matrices). The presence of such environment dramatically changes the overall properties of the nanoparticles system. , This initial observation triggered a number of both experimental and theoretical studies − to figure out the effect of matrix/particle interactions. Moreover, an unexpected widening of hysteresis loop has been detected in the case of microparticles embedded in various matrices, which was described as an effect of SC particle–matrix interactions .…”

Three states and three steps simulated within Ising like model solved by local mean field approximation in 3D spin crossover nanoparticles

“…Thus, it is worth considering that the processing of SCO materials with two inequivalent sites is hardly controllable, and thus makes the behavior of the high-spin fraction highly unpredictable. Recently, chemists started designing well controllable and reproducible SCO core-shell nanocomposites, but it is still nascent and might lead to instability due to large structural changes at the interface [19].…”