ИСТИНА

It is well-known that chemical reactions can be influenced by magnetic fields, which act to alter their rate, yield, or product distribution. These effects have been studied extensively in liquids, solids, and gases. They may be interpreted using the radical pair mechanism (RPM). Such effects are central to the field of spin chemistry of which there have been several detailed and extensive reviews [1, 2]. And much less publications presents the results of investigation of the dependence of nanoparticles morphology and structure on magnetic field effect at synthesis [3, 4]. Our investigations were carried out with the special reactor cell which was an element of the VSM, which controlled the magnetic moment of the samples. This experimental setup gives the possibility to control for ferromagnetic particles both the saturation magnetization and the coercive force of the samples during reduction, oxidation, and thermal decomposition. The ferromagnetic nanoparticles were prepared in our equipment by different methods: the thermal decomposition of cobalt formate in a flow of an inert gas that leds to the formation of cobalt nanoparticles in pores of various substrates (silica gel, alumina, activated carbon, and montmorillonite); the chemical reduction of the oxides in the hydrogen flow at different temperatures and so on. Electron microscopic studies showed that the particle-size distribution of cobalt depended on the external magnetic field value; the average particle size and distribution variance decreased as the field strength increased. The magnetic properties and composition stability were different for the samples prepared in magnetic field and without it. It was found that the thermo-programming reactions on cobalt reduction or oxidation changed under magnetic field effect. It was assumed that the external magnetic field affected the nucleation constant of nanoparticles.