SYNTHESIS AND ELECTRICAL CONDUCTIVITY OF SOLID SOLUTIONS OF THE SYSTEM PbF2–NdF3–SnF2
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Keywords

fluoride conductive phase, lead and tin fluorides, heterovalent substitution, fluoride neodymium, electrical conductivity, transport numbers.

How to Cite

Yuliia, P., Anatoliy, O., & Anton, N. (2020). SYNTHESIS AND ELECTRICAL CONDUCTIVITY OF SOLID SOLUTIONS OF THE SYSTEM PbF2–NdF3–SnF2. Ukrainian Chemistry Journal, 86(5), 24-37. https://doi.org/10.33609/2708-129X.86.5.2020.24-37

Abstract

In the system PbF2–NdF3–SnF2 are formed solid solutions of the heterovalent substitution Pb0,86-хNdхSn1,14F4+х (0 < x ≤ 0,17) with structure of β–PbSnF4. At x > 0,17 on the X-ray diffractograms, in addition to the basic structure, additional peaks are recorded to the reflexes of the individual NdF3. For single-phase solid solutions, the calculated parameters of the crystal lattice are satisfactorily described by the Vegard rule. The introduction of ions of Nd3+ into the initial structure leads to an increase in the parameter с of the elementary cell from 51.267 Å for x = 0,03 to 51.577 Å for x = 0.17. The replacement of a part of leads ions to neodymium ions an increase in electrical conductivity compared with Pb0.86Sn1.14F4. The slight replacement (3.0 mol. %) of Pb2+ ions by Nd3+ in the structure of Pb0.86Sn1.14F4 causes an increase in the electrical conductivity at T> 530 K (6.88·10-2 S/cm compared to 2.41·10-2 S/cm for the initial sample compound Pb0.86Sn1.14F4). In the region of lower temperatures, the electrical conductivity of the samples of this composition decreases, and below that temperature, on the contrary, slightly reduces the electrical conductivity, approaching the values characteristic of β-PbSnF4. The activation energy of the conductivity thus increases over the entire temperature range. A further increase in the concentration of Nd3+ ions in the synthesized samples causes an increase in their fluoride-ion conductivity throughout the temperature range. It should be noted that samples with a content of 10-15 mol% NdF3 at T>500 K have comparable conductivity values. At lower temperatures, the higher the conductivity, the higher the concentration of the substituent. The highest conductivity and the lowest activation energy have the sample Pb0.69Nd0.17Sn1.14F4.17373=3.68·10-2 S/сm, Ea=0,1 eV). The fluorine anions in synthesized phases are in three structurally-equivalent positions. The charge transfer is provided by the highly mobile interstitial fluorine anions, whose concentration increases with increasing temperature and concentration of NdF3. The transfer numbers for fluorine anions are not less than 0.99, practically independent of the concentration of neodymium trifluoride.

https://doi.org/10.33609/2708-129X.86.5.2020.24-37
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References

1. Gschwinda F., Rodriguez-Garciaa G., Sandbecka D.J.S., Grossa A., Weila M., Fichtner M., Hörmanna N. Fluoride ion bat-teries: Theoretical performance, safety, toxicity, and a combinatorial screening of new electrodes. Journal of Fluorine Chemistry. 2016. 182: 76.
2. Nakajima T., Groult H. Advanced Fluoride-Based Materials for Energy Conversion. (Elsevier, 2015). ISBN: 978-0-12-800679-5.
3. Zhang L., Anji M. Reddy, Fichtner M. Development of tysonite-type fluoride conducting thin film electrolytes for fluoride ion batteries. Solid State Ionics. 2015. 272: 39.
4. Rongeat C., Anji M. Reddy, Witter R., Fichter M. Nanostructured fluorite–type fluorides as electrolytes for fluoride ion batteries. The Journal of Physical Chemistry. 2013. 117: 4943.
5. Sorokin N.I., Sobolev B.P. Nonstoichio-metric fluorides-Solid electrolytes for electrochemical devices: A review. Crystallography Reports. 2007. 52 (5): 842.
6. Potanin A.A. Solid state chemical sourse based in ionic conductor type lanthan trifluoride. Russian Chemistry Journal. 2001. 45 (5–6): 58.
7. Sorokin N.I., Fedorov P.P., Nikol’skaya O.K., Nikeeva O.A., Rakov E.G., Ardashnikova E.I. Electrical properties of PbSnF4 materials prepared by different methods. Inorganic Materials. 2001. 37 (11): 1178.
8. Sorokin N.I., Fedorov P.P. Superionic materials based on lead fluoride. Inorganic Materials. 1997. 33 (1): 1.
9. Vakulenko AM, Uksha E.A. Electrical conductivity of solid electrolyte PbSnF4. Soviet Electrochemistry. 1992. 28 (9): 1257.
10. Kanno R., Nakamura S., Kawamoto Y. Ionic conductivity of tetragonal PbSnF4 substi-tuted by aliovalent cations Zr4+, Al3+, Ga3+, In3+ and Na+. Solid State Ionics. 1992. 52 (1–2): 53.
11. Pohorenko Yu.V., Pshenychnyi R.M., Omelchuk A.O., Trachevskii V.V. Conductivity of solid solutions of heterovalent substitution Pb1-xLnxSnF4+x (Ln=Y, La, Ce, Nd, Sm, Gd) with β-PbSnF4 structure. Solid State Ionics. 2019. 338: 80. (DOI: 10.1016/j.ssi.2019.05.001)
12. Mohammad, J. Chable, R. Witter, M. Fichtner, M. Anji Reddy // ACS Applied Energy Materials, 2018. (DOI: 10.1021/acsaem.8b00864)
13. Trnovcova T., Fedorov P.P., Furar I. Fluoride solid electrolytes. Russian Journal of Electrochemistry. 2009. 45 (6): 630.
14. Pogorenko Yu. V., Pshenichnyi R. N., Omel’chuk A. A., Trachevskii V. V. Electric conductivity of heterovalent substitution solid solutions of the (1–x)PbF2–xYF3–SnF2 system. Russian Journal of Electrochemistry. 2016. 52 (4): 374.
15. Погоренко Ю.В., Пшеничний Р.М., Павленко Т.В., Омельчук А.О. Синтез та електропровідність твердих розчинів KxPb1-xSnF4-x та KxPbSn1-xF4-x. Ukrainian Chemistry Journal. 2018. 84 (11): 20.
16. Погоренко Ю.В., Нагорний А.А., Пшеничний Р.М., Омельчук А.О.Синтез та електропровідність твердих розчинів системи RbF–PbF2–SnF2. Ukrainian Chemistry Journal. 2019. 85 (5): 60.
17. Wagner C. Galvanische Zellen mit festen Elektrolyten mit gemischter Stromleitung. Z. Elektrochem. 1956. 60: 4.
18. Urusov V.S. Theoretical Crystal Chemistry. Manual (Moscow: Mosk. Gos. Univ., 1987). [in Russian].
19. Irvine J.T.S, Sinclair D.C., West A.R. Electroceramics: characterization by imped-ance spectroscopy. Adv. Mater. 1990. 3: 132.
20. Jonscher A.K. The “universal” dielectric response. Nature. 1977. 267: 673.
21. Funke K. Jump relaxation in solid electrolytes. Progress in Solid State Chemistry. 1993. 22 (2): 111.
22. Ghosh A., Sural M. A new scaling property of fluoride glasses: Concentration and temperature independence of the conductivity spectra. Europhys. Lett. 1999. 47 (6): 688.
23. Ghosh A., Pan A. Scaling of the Conductivity Spectra in Ionic Glasses: Dependence on the Structure. Physical Review Letters. 2000. 84 (10): 2188.
24. Izosimova M.G., Livshits A.I., Buznik V.M., Fedorov P.P., Krivandina E.A., Sobolev B.P. Diffusion mechanism of fluorine ions in solid electrolytes having the tysonite structure. Soviet Physics Solid State. 1986. 28 (9): 1482.
25. Kavun V. Ya., Ryabov A. I., Telin I. A. et al. NMR and impedance spectroscopy data on the ionic mobility and conductivity in PbSnF4 doped with alkali metal fluoride. Journal of Structural Chemistry. 2012. 53 (2): 290.
26. Gabuda S.P., Gagarin Y., Polishchuk S.A. NMR of inorganic fluorides.(Moskow: Atomizdat, 1978). [in Russian].
27. Almond D.P., West A.R. Mobile ion concentrations in solid electrolytes from an analysis of a.c. conductivity. Solid State Ionics. 1983. 9–10 (Part 1): 277.

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