Effects of surfactants on the particle morphology and self-organization of Co nanocrystals

A synthesis method based in the principles of the so-called polyol process has been developed to prepare Co nanocrystals of 5, 8 and 20 average diameter. The influence of stabilizers, as oleic and lauric acids, on the morphology and the self-assembled aggregates of the final Co nanocrystals has been analysed, as well as on their magnetic properties. Rather spherical Co nanoparticles were obtained using oleic and lauric acid, respectively, with 8 and 5 nm in diameter and narrow particle size distribution. The lauric acid, having a shorter chain length, seems to be more effective in coating the particles. (C) 2003 Elsevier B.V. All rights reserved.