Structure of particle assembly in water-based magnetite magnetic fluid under zero applied field

The magnetic particle dispersion in magnetic fluid has been found to depend very much on the type of dispersing media. The water-based magnetic fluid has been found to contain large number of inherent clusters even in zero ap plied magnetic field. In this paper, we discuss the possible origin of thes e primary clusters and propose that these clusters are of magnetic origin. The scanning probe microscope observation of primary clusters were carried out and found to be of ring shape.