Mechanochemical synthesis of NaNbO3: A complementary study of reaction mechanism using Raman spectroscopy and quadrupole perturbed 23Na nuclear magnetic resonance

The mechanism of the mechanochemical reaction between Na2CO3 and Nb2O5, particularly the reaction course, was explored in detail. New data on the transitional (intermediate) phase of the reaction were obtained, including the characteristics of Nb―O bonding and chemical environment of Na+ ions. This was achieved by using analytical methods sensitive to the short-range (local) structural order, i.e., Raman and solid-state NMR spectroscopy. The paper demonstrates the importance of selecting a combination of appropriate analytical tools; through the example of mechanochemistry, we show these tools provide far enriched information on complex reaction mechanisms, like those encountered during processing involving amorphous phases.