Agglomeration of magnetite nanoparticles with citrate shell in an aqueous magnetic fluid

In this work, the aggregation of nanoparticles in an aqueous colloidal solution of magnetite, stabilized by creating a citrate shell on the particle surface is studied. Electron microscopy and laser correlation spectroscopy were used as experimental methods. Optical measurements were carried out both at zero external magnetic field and in the fields differently oriented relative to the probing laser beam. It is shown that the samples tend to form large aggregates even without the application of the field, and in the case of its presence the behavior of these structures has features that distinguish them from other magnetic fluids.