Object of investigation: systems EuF3 (EuF2)-MFx (MOx/2) (х = 2-4, M = Mg, Al, Pb, Sc, Hf). Aim of investigation: reception of optical film-forming materials with the refined optical and operational properties on the basis of fluorides of metals MFx (х = 2-4, M = Mg, Al, Pb, Sc, Hf) by their doping with europium (III) fluoride. Methods of investigation and instruments: thermogravimetric and differential thermal analysis, the X-ray phase analysis, spectroscopy of diffuse reflectance and luminescence spectroscopy, determination of a magnetic susceptibility by a Faraday method, chemical analysis, thermal evaporation in vacuum, spectrophotometry and refractometry of thin-film coats, definition of mechanical and thermal durability of coats. Theoretical and practical results, novelty: With use of radii of ions (taking into account a coordination number), their charges and ionicity of bonds the parametre for an estimation of basicity of metal-nonmetal bonds for fluorides and oxides is proposed, that makes possible to predict formation of the complex compounds (fluorides, oxides) and a direction of exchange reactions between fluorides and oxides of metals. It is established, that interaction in system EuF3-MgO proceeds under the scheme of an exchange reaction with formation of MgF2 and europium oxofluorides of a various composition. An essentially different character of reduction processes of system EuF3-MgF2 by elemental silicon in lack and in the presence of MgO with formation: in case of the former - EuF2 and SiF4, and in second - MgF2, EuF2, silicates or fluorosilicates of Eu (II) is established that is used for working out of method of determination of the content of MgO impurity in MgF2. The phenomenon of removal of oxygen-containing impurities by means of a redox reaction in the course of thermal evaporation in vacuum of samples of systems EuF3-MFx is revealed, that makes possible to obtain thin-film coats with exclusively high optical (scattering coefficient at level of 10-2-10-3 %) and operational (mechanical durability of group 0) properties. Field of application: inorganic chemistry.
