Control of the synthesis of magnetic fluids by relaxometry and magnetometry

Abstract The aim of this work is the development of a new and quick method for the quality control of magnetic fluids. The method is based on the analysis of proton nuclear magnetic relaxation dispersion curves which give the evolution of the relaxation rate of the solvent protons as a function of the magnetic field. These profiles provide physical information about the magnetic nanocrystals namely the average radius r and the specific magnetization Ms. This technique has been used to establish the conditions for reproducible and size controlled synthesis of dextran coated superparamagnetic nanomagnets.