Synthesis and characterization of perovskite-type [K1−xNax]MgF3 mixed phases via the fluorolytic sol-gel synthesis

Abstract

The focus of this article is the synthesis of perovskite-type [K1−xNax]MgF3 mixed phases via the room-temperature fluorolytic sol-gel approach. Different molar ratios of K/Na were examined and analyzed by19F MAS NMR and X-ray powder diffraction. Starting from pure KMgF3, a systematic substitution of potassium by sodium was evidenced when replacing K by Na. As long as the amount of sodium is less than 80% as compared to potassium, spectra just show [K4−xNaxF] environments in a [K1−xNax]MgF3 mixed phase but separate structures appear when the amount of sodium is further increased. Moreover, colloidal dispersions of nanoscaled KMgF3 particles were obtained, which were used to fabricate coatings on glass slides. Thin films showed antireflective behavior and high transmittance.