Initial susceptibilities of magnetic fluids dispersing Mn-Zn ferrite and cobalt ferrite particles

The magnetic and hydrodynamic properties of magnetic fluid depend on the micro behavior of the particles in the media. In this paper, we discuss the relaxation mechanism of Mn-Zn and cobalt ferrite particles in kerosene based magnetic fluid by measuring the initial susceptibilities in the temperature range of 83-293 K. The Mn-Zn ferrite magnetic fluid was found to consist almost only of superparamagnetic (SP) particles, where as the cobalt ferrite magnetic fluid consists of non-SP particles that relax through Brownian rotation for fields less than 440 Oe and influence the magnetic and hydrodynamic properties of the fluid.<
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