For many centuries, solid-state chemistry was limited to the same high-temperature chemistry used by the potters of yesteryear to prepare a wide variety of compounds. In the end, it was a social problem, and in particular the 1973 oil crisis, that led to its diversification and the development in France of a less energy-intensive low-temperature chemistry, now known throughout the world as "soft chemistry". This is a highly versatile type of chemistry, mainly carried out via solution using hydro(solvo)(iono)-thermal approaches, or involving microwave or sonification synthesis.
This lecture describes how to manipulate atoms via these various low- and high-temperature synthesis processes, and mentions their specificity for the development of value-added materials for energy-related applications. The approach taken to choosing precursors, temperature and even reaction atmosphere is also explained. The lecture is supplemented by seminars, each given by experts in the fields of X-ray, neutron, microscopy, EPR, NMR and XPS, who review the state of the art in these ex situ and in situ characterization techniques. They show that they are essential for detecting the arrangement of atoms, defects, local order and even the surface state of solids, with a view to better controlling their physical properties.