“…Examples of the structures of highly dispersed Ca Recently, the solution combustion (SCS) method has been used to obtain new nanostructured multiferroic materials with unique magnetic, electrical, and catalytic properties based on rare-earth element (REE) orthoferrites RFeO 3 (R = Y, Ln) [194,207,231,297,[303][304][305][306][307][308][309][310] with a perovskite-like structure, combining ferromagnetic and ferroelectric ordering. In some cases, it has been shown that the use of additional heat treatment of solution combustion products and other chemical precursors leads to the formation of metastable forms of REE orthoferrites and a significant change in the functional characteristics of materials based on them [231,311,312]. It has been shown that in this case, the chemical and structural background of the precursor exposed to thermal action plays an important role [313][314][315][316], while for other systems, for example, KNO 3 -BaTiO 3 -based ferroelectrics, the necessary properties can be achieved by simple mechanical mixing of the components and the background does not play a significant role [317].…”