Milling and Mechanochemical Synthesis

The mechanical activation and mechanochemical synthesis as the direction of solid-phase synthesis has been developing for over a century. Synthesis of nanoparticles has become popular due to development of new attrition mills and other devises for materials grinding under high mechanical energy conditions. The best results in mechanochemistry and mechanoactivation have been achieved in scientific groups of P.Y. Butyagin and V.V. Boldyrev [24, 25]. 

The advantages of the mechanochemical synthesis of ferroelectric powders are as follows (i) direct synthesis of nanoscale powders showing better sintering behavior, (ii) reaction sintering due to decomposition of the precursor, (iii) amorphization of precursors, and (iv) grinding of precursors. 

Dispersion process in the attrition mill with high energy intensity is described by the relation 

The nanoparticles of ferromagnetic materials such as Ni, Co, Fe can be obtained from their salts such as chlorides by mechanical activation followed by reduction of metal with sodium  

The result of such exothermal reaction with significant heat release is an iron powder with a particle size of 10-20 nm. In accordance with Refs. [65,66], the coalescence of as-prepared nanoparticles during the reaction can be prevented using sodium chloride additive. The reduction of cobalt and nickel from chlorides are listed in 

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I.V. Uvarova, M.P. Savyak, I.M. Zabrodsky, D.P. Ziatkewych, L.P. Isaewa, 1.1. Timofeewa. Mechanical milling and mechanochemical synthesis of refractory compounds. Nanostructure materials. Physical chemical foundations of powder metallurgy technology. Kyiv 2003. 

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