On the utility of low frequency, polarised, complex susceptibility measurements in the investigation of the dynamic properties of magnetic fluids

Abstract The measurement of the field and frequency-dependent, complex susceptibility, χ (ω, Η) = χ′(ω, H) − iχ″ (ω, Η), is an established method for investigating the dynamic properties of magnetic fluids. Polarised measurements have been used to investigate many properties of magnetic fluids, including, relaxation mechanisms, aggregation, magnetic losses, loss factor tanδ, power factor sinδ, and the influence which polarising fields may have on the hysteresis and isotropic properties of samples. In this paper, a review is given of these topics and typical results are presented.

[1]  S. Charles.  AGGREGATION IN MAGNETIC FLUIDS AND MAGNETIC FLUID COMPOSITES , 1988 .

[2]  B. Scaife,et al.  The measurement of the frequency dependent susceptibility of magnetic colloids , 1988 .

[3]  J. W. Brown.  Thermal Fluctuations of a Single-Domain Particle , 1963 .

[4]  R. E. Rosensweig,et al.  Heating magnetic fluid with alternating magnetic field , 2002 .

[5]  P. Scholten.  How magnetic can a magnetic fluid be , 1983 .

[6]  V. Socoliuc,et al.  Agglomerate formation in moderately concentrated ferrofluids from static magneto-optical measurements , 1999 .

[7]  W. Brown.  Thermal Fluctuations of a Single‐Domain Particle , 1963 .

[8]  P. G. de Gennes,et al.  Pair correlations in a ferromagnetic colloid , 1970 .

[9]  P. C. Fannin,et al.  The study of a ferrofluid exhibiting both Brownian and Neel relaxation , 1989 .

[10]  B. Scaife,et al.  RAPID COMMUNICATION: New technique for measuring the complex susceptibility of ferrofluids , 1986 .

[11]  M. Shliomis.  REVIEWS OF TOPICAL PROBLEMS: Magnetic fluids , 1974 .

[12]  P. C. Fannin.  An experimental observation of the dynamic behaviour of ferrofluids , 1994 .

[13]  B. Scaife,et al.  The field dependence of the complex frequency-dependent susceptibility of magnetic fluids , 1988 .

[14]  P. C. Fannin,et al.  Investigation of magnetic fluids exhibiting field-induced increasing loss peaks , 2010 .

[15]  K. Cole,et al.  Dispersion and Absorption in Dielectrics I. Alternating Current Characteristics , 1941 .

[16]  A. T. Giannitsis,et al.  Frequency-dependent loss tangent and power factor of magnetic fluids , 2001 .