Anionic conductivity and thermal stability of single crystals of solid solutions based on barium fluoride

Ion Transfer in CdF2-based Iso- and Polyvalent Solid Solutions

“…A similar dependence for isoconcentration series M 0.8 R 0.2 F 2.2 (M = Ca, Sr, Ba) was observed in [1,19]. In Cd 0.9 R 0.1 F 2.1 , as in M 0.8 R 0.2 F 2.2 , clusters of point defects form at high contents of R 3+ .…”

“…Among them, polyvalent solid solutions M 1 -x R x F 2 + x (M = Ca, Sr, Ba, Cd, Pb; R = La-Lu, Y, Sc, In) with the structure of fluorite ( Fm m group) attract much attention. The ionic conduction in these phases is caused by migration of defects in the anionic sublattice [1,2]. Severe distortions of stoichiometry of MF 2 result in an exceptional structural organization of anion-excessive crystals of M 1 -x R x F 2 + x .…”

“…In more concentrated solutions, complicated complexes of structure defects called clusters [3] form. These accumulate cationic and anionic defects ( , , various types of interstitial ions ) and strongly affect the ion transfer in the fluorite structure [1].…”

Electrical properties of heavily doped fluorite-structured BaF2:RF3 (R=La, Pr, Nd, Gd, Tb, Y, Sc) single crystals

“…2). The same behavior was observed in [16,23]. Upon doping with Nd ~+, Gd 3+, Tb 3 § y3+ and Sc 3+ ions, a maximum is observed in the concentration dependence of the ionic conductivity, at 10 -20 mole-% RF 3 ( Fig.…”

Impedance of the Ag|Nd0.95Sr0.05F2.95 Crystal|Ag System

“…The impedance was measured (in a two-electrode circuit) with a Solartron 1260 spectra analyzer at 10 -1 to 10 7 Hz (signal 30 mV). The measurements were performed under nitrogen at 320 − 1072 K and in a vacuum (10 -3 Pa) at 94-372 K. The temperature was measured to an accuracy of ± 0.1 K. The stabilization time at each temperature was 1 to 2 h. The setup is described at length in [8,9]. Electronic conduction contributes but negligibly to the full conduction, as it follows from a blocking effect of the Ag electrodes observed in the impedance spectra and from the fact that the admittance curve crosses the origin; this finding agrees with [4,5,10,11].…”