Colloidal characterization of micron-sized rod-like magnetite particles

Rod-like magnetite particles have been prepared following a precipitation procedure in the presence of an external magnetic field. These particles have been characterized and results compared to those obtained for spheres which were synthesized following the same recipe but in the absence of a magnetic field. Both spheres and rod-like particles have a saturation magnetization of 475 kA/m, an isoelectric point at approximately pH 6.6, and a magnetite inverse spinel structure. DLVO theory qualitatively predicts the results obtained regarding the stability of the magnetite dispersions.