Polarizing Field and Particle ConcentrationDependence of the Magnetic Loss Power inFerrofluids

摘要

The frequency (f) and polarizing field (H) dependence of the complex magneticpermeability μ(f, H) = μ(- i μ(H),of different magnetic fluid samples, over the range100 MHz to 6 GHz and 0 to 102.4 kA/m, respectively, were analyzed. Starting from an initialmagnetic fluid sample (sample A) with magnetite particles dispersed in kerosene and stabilizedwith oleic acid, having particle concentration n = 19.1610(22)m(-3),three samples were obtained bysuccessive dilution with kerosene (with a dilution ratio 2:3) (samples Al, A2, and A3). Based onthe complex magnetic permeability measurements of each sample, and for each field value,values of the specific magnetic loss power were obtained. We have also studied the dependenceon particle concentration of the magnetic loss power, both in zero polarizing field and in thepresence of the polarizing field.