Подвижность носителей заряда в монокристалле и нанокерамике ионного проводника Sr-=SUB=-1-x-=/SUB=-Y-=SUB=-x-=/SUB=-F-=SUB=-2+x-=/SUB=- (x=0.3)

The heterovalent solid solution Sr1−xYxF2+x with fluorite structure (sp. gr. Fm-3m) can be synthesized in single-crystal and nanoceramic forms. Comparison of their electrical properties shows that nanoceramics have a higher ionic conductivity than single crystals the same composition. In the single-crystal state of the solid solution, the migration mechanism dominates interstitial ions F' in the bulk of the sample, in the nanoceramic state ther is the vacancy migration mechanism V• along the grain boundaries of the sample. Using electrophysical and structural data, we calculated mobility μmob and concentration nmob of ionic charge carriers in a single crystal (a = 0.5722 nm) and ceramics (a = 0.57442 nm) of composition Sr0.7Y0.3F2.3. The defect mobility F′ (μmob = 4.5 10−10 cm2/(V s) at 500 K) in a single crystal is less than the mobility of vacancies V• in nanoceramics by 140 times. The concentration charge carriers is nmob = 1.1 1021 and 6.9 1021 cm-3 (2.2 and 14.2% of the total number of anions) for single crystal and nanoceramics, respectively.