Magnetic nanoparticle clusters with magnetization of about 80 emu/g and tunable size between 55 and 500 nm were synthesized through a bisolvent solvothermal process in the presence of ethylene glycol (EG) and diethylene glycol (DEG), triethylene glycol (TEG) or 1,2-propanediol (PG) with polyethylene glycol (PEG) or hexadecyltrimethyl ammonium bromide (CTAB) as surfactant. It was found that the volume ratio of EG to the other polyol played an important role in controlling the size and morphology of Fe3O4. Effect of the concentration of Ferric chloride hexahydrate (FeCl3.6H(2)O) and original reactants on controlling the size of Fe3O4 particles was also discussed. (C) 2016 Elsevier B.V. All rights reserved.