Title :
Initial susceptibilities of magnetic fluids dispersing Mn-Zn ferrite and cobalt ferrite particles
Author :
Nakatsuka, K. ; Jeyadevan, B.
Author_Institution :
Dept. of Resources Eng., Tohoku Univ., Sendai, Japan
fDate :
11/1/1994 12:00:00 AM
Abstract :
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
Keywords :
cobalt compounds; ferrites; magnetic fluids; magnetic particles; magnetic relaxation; magnetic susceptibility; manganese compounds; superparamagnetism; zinc compounds; 83 to 293 K; Brownian rotation; Co ferrite particles; CoFe2O4; Mn-Zn ferrite; MnZnFe2O4; hydrodynamic properties; initial susceptibilities; kerosene; magnetic fluids; magnetic properties; microbehavior; relaxation mechanism; superparamagnetic particles; Cobalt; Ferrites; Hydrodynamics; Magnetic field measurement; Magnetic liquids; Magnetic properties; Magnetic susceptibility; Particle measurements; Rotation measurement; Temperature distribution;
Journal_Title :
Magnetics, IEEE Transactions on
