Abstract Using the complex dielectric permittivity measurements, in the frequency range 20 Hz – 2 MHz and at temperatures between (25–70) ∘C, the polarizability (α), the electric modulus (M) and the electrical conductivity (σ), of a ferrofluid sample, were determined. The results enabled the computation of the thermal activation energy of electrical conduction, the obtained value being approximately equal, at 0.15 eV. By eliminating the losses arising from electrical conduction, we highlighted the existence of a Schwarz type dielectric relaxation, in the sample, at the frequency above 5 kHz. These results allowed, for the first time, the evaluation of the mechanical mobility, u, of the ions on the particle surface, resulting in a value of, u = 3.4 ⋅ 10 8 m/s N. Knowledge of macroscopic and microscopic electrical properties is useful in explaining the dielectric polarization mechanisms and relaxation processes of ferrofluids, and also in the use of ferrofluids in technological and biomedical applications.

中文翻译：

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低频场中铁磁流体的宏观和微观电学特性

摘要 使用复介电常数测量，在 20 Hz – 2 MHz 频率范围内和 (25–70) ∘C 之间的温度下，极化率 (α)、电模量 (M) 和电导率 (σ)，铁磁流体样品，被确定。结果能够计算导电的热活化能，获得的值大约等于 0.15 eV。通过消除由导电引起的损耗，我们强调了样品中频率高于 5 kHz 时 Schwarz 型介电弛豫的存在。这些结果首次允许对粒子表面离子的机械迁移率 u 进行评估，得出的值为 u = 3.4 ⋅ 10 8 m/s N。