Ordering is used as a technique to make a nanostructure in compact and disperse A_yB_1-y solid solutions (alloys) and MX_y nonstoichiometric compounds (where M is the transition d-metal, X = C, N, O, y <1.0) by means of the first kind of order-disorder phase transformation that is accompanied by the volume change. The ordering process is diffusive, and therefore transformation is not instantaneous, taking place within several dozens of minutes or hours. When cooled down from the synthesis temperature to room temperature, solid solutions or nonstoichiometric compounds pass through the ordering temperature. Due to the difference in lattice between the disordered and ordered phases, there evolve stresses in the material, which can lead to the cracking of crystallites at the interface of the disordered and ordered phases.