On the permeability of a magnetodielectric emulsion

The effects of magnetic felds on the properties of ferrofluids and ferrogels

“…The dependence of the magnetic permeability of ferrofluid emulsions on the external magnetic field strength is illustrated in Fig. 2 in comparison with the experimental data [7]. Two emulsions with different volume fractions of ferrofluid droplets were studied: ϕ = 0.2 and 0.35.…”

“…Recently, such nonmonotonic field dependence of the magnetic permeability has been experimentally reported [7] for ferrofluid emulsions (Fig. 2, experimental dots) produced by dispersing a kerosene-based ferrofluid in immiscible aviation oil.…”

“…The numerical solution of the set of equations (3), (5), (7), and (10) gives us, first, the degree of the droplet elongation induced by the applied magnetic field. The calculated typical ellipticity (long-to-short semi-axis ratio) is shown in Fig.…”

“…Field dependence of the magnetic permeability of ferrofluid emulsion. Experimental data [7] are presented for the emulsions with the droplet volume fraction ϕ = 0.2 (boxes) and 0.35 (circles). Theoretical predictions are shown by lines for the same emulsions.…”

“…The maximum value of the effective emulsion permeability increases with the volume concentration ϕ of the droplets. During measurements, the coalescence of the droplets was not experimentally observed [7]. The correct theoretical description of this nonmonotonic dependence needs a solution of the droplet elongation problem with account for the nonlinear magnetization of the droplet.…”