“…The heterovalent substitution mechanism for the formation of the aforementioned solid solutions (Fig. 2) can be described by the following equation: Nanofluorides are another rapidly developing area of the modern science [34][35][36][37][38][39], for nanofluorides are widely implemented as luminophores, catalysts, biomedical and electrochemical materials; the CaF 2 -YF 3 system has also become crucially important in this area, as well. Low-temperature and soft chemistry syntheses of nanofluorides (e.g, mechanochemical [40,41], sol-gel [24], solvothermal [42] methods and some other techniques [35]) are especially prominent because of their technological advantages.…”