Ionic mobility and electrophysical properties of solid solutions in PbF2–SbF3 and PbF2–SnF2–SbF3 systems

Mechanochemistry of fluoride solids: from mechanical activation to mechanically stimulated synthesis

“…The influence of high-energy ball milling on crystalline CaF 2 was studied in our group [61] and also later by Abdellatief et al [62]. The main analytical techniques used were X-ray powder diffraction, 19 F solid-state NMR, but also transmission electron microscopy (TEM). One important result, especially in comparison with oxide compounds, is a missing detectable amorphization of the fluoride powder samples after milling.…”

“…The mechanochemical synthesis of fluorides with inverse perovskite structure like BaLiF 3 [31][32][33][34] or (Ba,Sr)LiF 3 [35,36] was very successful. The mutual substitution of Ba 2+ with Sr 2+ ions was impressively demonstrated using high-speed 19 F magic angle spinning (MAS) NMR spectra (Fig. 4), which allowed the distinct discrimination between the five possible local structure units around fluorine.…”

“…Staring from crystalline SnF 2 and PbF 2 , both are well known as very good fluoride ion conductors, ternary and quaternary fluorides have been mechanochemically synthesized [19][20][21]. The systems MF 2 -SnF 2 (MSnF 4 , M: Pb, Ba) are the fastest fluoride ion conductors known nowadays [22][23][24].…”

“…Only nanocrystalline CaF 2 particles are obtained by applying even strongest mechanical impacts. Beside a broadening of the X-ray reflections and 19 F resonances, the spin lattice relaxation time T 1 of the 19 F nuclei gives a sensitive indication for the influence of the mechanical impact [61,62]. While for the commercial crystalline CaF 2 a T 1 time ( 19 F) of 91.2 s was determined, 4 h of milling in a planetary ball mill decrease this time to 3.9 s [61].…”

“…x ], with 0 ≤ x ≤ 4. Exemplarily, a 19 F MAS NMR spectrum of Sr 0.5 Pb 0.5 F 2 with all five possible fluorine coordinations and their respective assignments is shown in Fig. 11.…”