A refined theory of magnetoelastic buckling matches experiments with ferromagnetic and superparamagnetic rods.
Fabien Gerbal,Fabien Gerbal,Yuan Wang,Florian Lyonnet,Florian Lyonnet,Jean-Claude Bacri,Thierry Hocquet,Thierry Hocquet,Martin Devaud +8 more
TLDR
A magnetic “stick–slip” model is proposed to explain the sudden bending transition of an elastic rod experiencing a uniform induction field applied at a normal angle with respect to its long axis and it is demonstrated that the magnetoelastic buckling corresponds to a classical Landau second-order transition.Abstract:
In its simplest form the magnetoelastic buckling instability refers to the sudden bending transition of an elastic rod experiencing a uniform induction field applied at a normal angle with respect to its long axis. This fundamental physics phenomenon was initially documented in 1968, and, surprisingly, despite many refinements, a gap has always remained between the observations and the theoretical expectations. Here, we first renew the theory with a simple model based on the assumption that the magnetization follows the rod axis as soon as it bends. We demonstrate that the magnetoelastic buckling corresponds to a classical Landau second-order transition. Our model yields a solution for the critical field as well as the shape of the deformed rods which we compare with experiments on flexible ferromagnetic nickel rods at the centimeter scale. We also report this instability at the micrometer scale with specially designed rods made of nanoparticles. We characterized our samples by determining all of the relevant parameters (radius, length, Young modulus, magnetic susceptibility) and, using these values, we found that the theory fits extremely well the experimental results for both systems without any adjustable parameter. The superparamagnetic feature of the microrods also highlights the fact that ferromagnetic systems break the symmetry before the buckling. We propose a magnetic “stick–slip” model to explain this peculiar feature, which was visible in past reports but never detailed.read more
Citations
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References
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Journal ArticleDOI
Preparation and properties of monodisperse magnetic fluids
TL;DR: In this article, a size sorting method performed on ionic magnetic fluids, constituted by polydisperse anionic particles dispersed in water at pH 7, allows "monodisperse" samples to be obtained.
Journal ArticleDOI
Experiments and modeling of iron-particle-filled magnetorheological elastomers
TL;DR: In this article, a combined experimental and theoretical study of the macroscopic response of a particular MRE consisting of a rubber matrix phase with spherical carbonyl iron particles is presented.