Synthesis and study of γ-Fe 2 O 3 and CoFe 2 O 4 based ferrofluids by means of spectroscopic Mueller matrix ellipsometry

Yann Battie (1) , Michel Stchakovsky (2) , Sophie Neveu (3) , Damien Jamon (4) , Enric Garcia-Caurel (5)

1 LCP-A2MC - Laboratoire de Chimie et Physique - Approche Multi-échelle des Milieux Complexes
2 HORIBA France SAS [Longjumeau]
3 PHENIX - PHysicochimie des Electrolytes et Nanosystèmes InterfaciauX
4 LHC - Laboratoire Hubert Curien
5 LPICM - Laboratoire de physique des interfaces et des couches minces [Palaiseau]

Ferrofluids are colloidal suspensions generally composed of ferromagnetic or ferrimagnetic nanoparticles (NPs). In the present study, the authors have focused on the ellipsometric characterization of two types of ferrofluids: one constituting maghemite (γ-Fe2O3) NPs and the other cobalt ferrite (CoFe2O4) NPs. The optical properties of the NPs are extracted from the ellipsometric spectra by using the Maxwell–Garnett effective medium approximations. As expected, Mueller matrix measurements reveal that the ferrofluid becomes anisotropic under the influence of a magnetic field. The authors correlate this anisotropy to the preferential orientation of NPs along the magnetic field.

Domains: Physics [physics]

Yann Battie, Michel Stchakovsky, Sophie Neveu, Damien Jamon, Enric Garcia-Caurel. Synthesis and study of γ-Fe 2 O 3 and CoFe 2 O 4 based ferrofluids by means of spectroscopic Mueller matrix ellipsometry. Journal of Vacuum Science & Technology B, Nanotechnology and Microelectronics, 2019, 37 (6), pp.062929. ⟨10.1116/1.5121286⟩. ⟨ujm-02396890⟩