Comment on “Measuring the transverse magnetization of rotating ferrofluids”

Contrary to the main conclusion of Embs et al. [Phys. Rev. E 73, 036302 (2006)], we demonstrate with amplitude correction factors that the predictions of the magnetization model proposed by Shliomis [Sov. Phys. JETP 34, 1291 (1972)] are well consistent with the experimental data for weakly nonequilibrium states and that the model proposed by Shliomis [Phys. Rev. E 64, 063501 (2001)] is valid even far from equilibrium. A model on the basis of the weak-field magnetization equation of Müller and Liu [Phys. Res. E 64, 061405 (2001)] with a “structure” modification is also shown to reproduce a wide range of experimental data. Our statement is confirmed by a more exact insight into the hydrodynamic problem of rotating ferrofluids.

Figure 1

Comparison of the experimental data of the transverse local equilibrium field strength measured by the sensor at the applied magnetic field $h_0=30\mathrm{kA}∕\mathrm{m}$ with the numerical results according to different theoretical models. The fit parameters used for the Sh72, Feld, and Sh01 models are shown in Table I of Embs et al. [14], and those used for the MRSh, Weng-Chen (WC), and ML models are the same as the Sh01 model.