A Crystallographic Contribution to the Mechanism of a Mechanically Induced Solid State Reaction

Abstract

Using X-ray diffraction analysis and Raman spectroscopy techniques, a mechanically induced double displacement reaction has been used to investigate the chemical mechanism by which mechanical alloying occurs. The specific reaction studied was the reduction of cupric oxide by iron. From Rietveld analysis of milled powders, isotropic atomic displacement parameters are refined and the lattice strain involved in displacing oxygen in the CuO lattice is then calculated. In addition, anisotropic atomic displacement parameters are refined, providing information regarding the reaction pathway. Raman spectroscopy is used to differentiate between thermal motion and static displacement of oxygen atoms in the CuO lattice. Using this information, the mechanism of a mechanically induced solid state reaction is described.