Аннотация:Mössbauer studies of bioreduction products stabilized by acetone and ethanol were carried out at wide temperature range (from 80 K to room temperature) and in external magnetic field applied perpendicular to γ-beam (at room temperature). The initial products (mixture of nonstoichiometric magnetite and maghemite) were formed during iron reduction of synthesized ferrihydrite by bacterium G. ferrihydriticus. Addition of acetone and ethanol led to slight decrease of the particles size. The particles average size and magnetic moment were 11.2 nm and 524 μB,respectively.