Elasticity of Prussian‐Blue‐Analogue Nanoparticles

Abstract

Abstract:We report on the elastic properties of Ni/[Fe(CN) 6 ] Prussian-blue-analogue nanoparticles investigated by highpressure synchrotron X-ray diffraction and nuclear inelastic scattering. For 3 nm and 115 nm particles, we have obtained bulk moduli of (30.3 ± 3.8) GPa and (24.5 ± 3.2) GPa, with Debye sound velocities of (2496 ± 46) m s -1 and (2407 ± 38) m s -1, re-

Complete Set of Elastic Moduli of a Spin-Crossover Solid: Spin-State Dependence and Mechanical Actuation

“…Prussian blue analogue complex Ni/[Fe(CN)6] and a value of v = 0.35 was found. [43] It may be worth to note also that for v = 0.33 one obtains B = Y. In addition, the temperature dependences of the isotropic bulk and Young's moduli are the same, hence the Poisson's ratio is temperatureindependent within this approximation.…”

Spin Crossover Nanomaterials: From Fundamental Concepts to Devices

“…For example, in the case of RbCoFe@KCoCr PBA heterostructures the increase of the shell thickness led to a depression of the transition temperature of the core, which can be accounted for by the fact that the lattice parameter of the shell matches more closely the lattice parameter of the core in the HS state . It is interesting to note, however, that depending on the sign of the volume misfit this latter can stabilize either the HS or the LS state . Despite their undeniable advantages, common microscopic models of SCO remain often difficult to link with experiments in a quantitative manner.…”

“…To this aim continuum mechanics provides a significant advantage because it can be used to calculate the interface elastic strain using experimental data (thermal and elastic constants). This was recently demonstrated through the calculation of the deformation energies of hollow and core–shell particles by solving the Navier equation . An expression of the pressure at the particle surface/interface was analytically derived linking the interface elastic strain to the morphology and mechanical properties (Young's modulus, Poisson's ratio) of the particle.…”

“…An expression of the pressure at the particle surface/interface was analytically derived linking the interface elastic strain to the morphology and mechanical properties (Young's modulus, Poisson's ratio) of the particle. In light of these advances, the experimental investigation of mechanical properties of SCO (nano)materials becomes imperative …”

“…Overall, the most encouraging (and somewhat unexpected) experimental result obtained with these different nanoscale SCO materials is that the hysteresis and a virtually complete spin transition can be preserved even in very small objects (<5 nm) . On the other hand, experiment revealed a range of different behaviors (vide infra), which have not yet been fully rationalized, despite the development of several thermodynamical, continuum mechanics, and statistical physics approaches to this aim. This problem will be addressed in the second part of this review, while the third part will be devoted to examples of successful integration of SCO nanomaterials into devices.…”