AC Susceptibility Measurements in the Investigation of Aggregation in Magnetic Fluids

• Authors: P. Fannin , S. Charles
• Languages of publication: EN

Abstracts

EN

Measurements of the complex, frequency dependent susceptibility, χ(ω)=χ '(ω)-iχ''(ω) of two water based magnetic fluids, over the frequency range 10 Hz to 1 MHz are reported. Plots of the susceptibility components against log[f(Hz)] are found to have approximate Debye-type profiles with the presence of Brownian relaxation being indicated by the frequency, f_{max}, of the maximum of the loss-peaks in the χ''(ω) profiles. Corresponding calculations of particle hydrodynamic radius indicate the presence of aggregation. Frohlich, normal and lognormal distribution functions are used to obtain an estimate of the aggregate size distribution in the samples.

Keywords

EN

75.50.Tt; 76.20.+q

Discipline

• 76.20.+q: General theory of resonances and relaxations
• 75.50.Tt: Fine-particle systems; nanocrystalline materials

• Publisher: Institute of Physics, Polish Academy of Sciences
• Journal: Acta Physica Polonica A
• Year: 2000
• Volume: 97
• Issue: 3
• Pages: 591-594

Dates

published

2000-03

Contributors

author

P. Fannin

• Dept. of Electronic & Electrical Engineering, Trinity College Dublin 2, Ireland

author

S. Charles

• Dept. of Chemistry, University College of North Wales, Bangor, LL57 2UW, UK

Identifiers

DOI

10.12693/APhysPolA.97.591