In situ magnetorheological SANS setup at Institut Laue-Langevin

Abstract

A magnetorheological sample environment is presented that allows for in situ magnetic field and shear flow during small-angle neutron scattering (SANS) measurements and is now available at the Institut Laue-Langevin (ILL). The setup allows performing simultaneous magnetorheological measurements together with the investigation of structural and magnetic changes on the nanometer length scale underlying the rheological response of ferrofluids. We describe the setup consisting of a commercial rheometer and a custom-made set of Helmholtz coils and show exemplarily data on the field and shear flow alignment of a dispersion of hematite nanospindles in water.

Controlling the rotation modes of hematite nanospindles by dynamic magnetic fields

“…31 Small-angle scattering probes nanoscale inhomogeneities with suitable spatial resolution to address the orientation distribution of a nanoparticle ensemble, 25,32,33 whereas timeresolved approaches give versatile opportunities to study in-situ nanoparticle ensemble dynamics. [34][35][36] Stroboscopic SAXS provides the necessary time resolution to monitor changes in the orientation distribution near the characteristic frequencies. We therefore performed time-resolved SAXS at the microfocus beamline ID13 (ESRF) to monitor the dynamic fielddependent orientation of hematite spindles driven by a custom-made set of Helmholtz coils.…”

Controlling the rotation modes of hematite nanospindles using dynamic magnetic fields

“…35 Small-angle scattering is the most suitable technique to probe inhomogeneities on the nanoscale, with suitable spatial resolution to address the orientation distribution of a large ensemble of nanoparticles, [36][37][38] whereas time-resolved approaches give versatile opportunities to study in situ nanoparticle dynamics. [39][40][41] Stroboscopic SAXS provides the necessary time resolution to monitor changes in the orientation distribution near the characteristic frequencies of our nanoscale particles. We therefore performed time-resolved SAXS at the microfocus beamline ID13 (ESRF) to monitor the dynamic eld-dependent orientation of hematite spindles driven by a custom-made set of Helmholtz coils.…”

Using small-angle scattering to guide functional magnetic nanoparticle design

“…the strong increase in viscosity with magnetic eld, has been investigated with in situ magnetorheology and small-angle scattering investigating the orientational order. 174,175 Shear-thinning behavior is explained by the disruption of the so aggregates for high Fig. 6 (a) The collective properties in superparticles strongly depend on the packing order ranging from amorphous to supercrystalline with well-defined interparticle spacing.…”