Reproducibility of the Synthesis of Iron Oxide Nanoparticles Produced by Laser Pyrolysis

During the development of the BONSAI Project, the need for high quantities of iron oxide nanoparticles with some specific characteristics intensified the problem of the reproducibility in the nanoparticle production. Given the fact that the reaction yield for the production of the smallest and more homogeneous nanoparticles (BONFEX4) was very low (in the range of 1g/day), the process had to be repeated several times. These repetitions involved the use of three different CO(2) lasers (two of monomodal gaussian beams TEMoo mode with spot sizes of 4 and 3.5 mm and one multimodal of 4 mm spot size). Keeping constant the rest of the experiment parameters (including the laser density) we obtained similar powders in nature as revealed by X-ray diffraction, and similar particle size distributions, but with different magnetic properties. When the same laser was used the reproducibility of the magnetic properties increased significantly.