Abstract
The nonstoichiometric phases La1 − y Ca y F3 − y (y = 0.15, 0.20) with a tysonite (LaF3) structure have been prepared for the first time by the mechanochemical synthesis from CaF2 and LaF3 crystals. The average size of coherent scattering regions is approximately equal to 10–30 nm. It has been shown that the compositions of the phases prepared by the mechanochemical synthesis are inconsistent with the phase diagram of the CaF2-LaF3 system. The “mechanohydrolysis” of the La1 − y Ca y F3 − y phase has been observed for the first time. Under these conditions, the La1 − y Ca y F3 − y phase partially transforms into lanthanum calcium oxyfluoride for a milling time of 180 min with intermediate sampling. The La1 − y Ca y F3 − y nanoceramic materials have been prepared from a powder of the mechanochemical synthesis product by pressing under a pressure of (2–6) × 108 Pa at room temperature. The electrical conductivity of the synthesized materials at a temperature of 200°C is equal to 4.9(6) × 10−4 S/cm, and the activation energy of electrical conduction is 0.46(2) eV. These data for the nanoceramic materials coincide with those obtained for migration of fluorine vacancies in single-crystal tysonite fluoride materials.
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B. P. Sobolev, I. A. Sviridov, V. I. Fadeeva, et al., Kristallografiya 50(3), 536 (2005) [Crystallogr. Rep. 50 (3), 478 (2005)].
B. P. Sobolev and P. P. Fedorov, J. Less-Common Met. 60(1), 33 (1978).
P. P. Fedorov and B. P. Sobolev, J. Less-Common Met. 63(1), 31 (1979).
M. Svantner, E. Mariani, P. P. Fedorov, and B. P. Sobolev, Krist. Tech. 14(3), 365 (1979).
E. V. Shelekhov and T. A. Sviridova, Materialovedenie, No. 10, 13 (1999).
S. N. Sulyanov, A. N. Popov, and D. M. Kheiker, J. Appl. Crystallogr. 27, 934 (1994).
J. Rodriguez-Carvajal, FullProf: A Program for Rietveld Refinement and Pattern Matching Analysis (Laboratoire Leon Brillouin, Gif-sur-Yvette, France, 2004).
O. Greis and M. Kieser, Z. Anorg. Allg. Chem. 479, 165 (1981).
B. P. Sobolev, V. B. Aleksandrov, P. P. Fedorov, et al., Kristallografiya 21(1), 96 (1976) [Sov. Phys. Crystallogr. 21 (1), 49 (1976)].
A. K. Ivanov-Shits, N. I. Sorokin, P. P. Fedorov, and B. P. Sobolev, Fiz. Tverd. Tela (Leningrad) 25(6), 1748 (1983) [Sov. Phys. Solid State 25 (6), 1007 (1983)].
M. Leoni, G. de Giudici, R. Biddau, et al., Z. Kristallogr. 23(Suppl.), 111 (2006).
B. P. Sobolev, The Rare-Earth Trifluorides, Part 2: Introduction to Materials Science of Multicomponent Metal Fluoride Crystals (Shubnikov Institute of Crystallography, Russian Academy of Sciences, Moscow, 2001; Institut d’Estudis Catalans, Barcelona, 2001).
N. I. Sorokin and B. P. Sobolev, Kristallografiya 39(5), 889 (1994) [Crystallogr. Rep. 39 (5), 810 (1994)].
M. G. Izosimova, A. I. Livshits, V. M. Buznik, et al., Izv. Akad. Nauk SSSR, Neorg. Mater. 23(11), 2056 (1987).
N. I. Sorokin and B. P. Sobolev, Élektrokhimiya 43(4), 420 (2007) [Russ. J. Electrochem. 43 (4), 398 (2007)].
N. I. Sorokin, E. A. Krivandina, Z. I. Zhmurova, et al., Fiz. Tverd. Tela (St. Petersburg) 41(4), 638 (1999) [Phys. Solid State 41 (4), 573 (1999)].
V. V. Zyryanov and N. F. Uvarov, Neorg. Mater. 40(7), 835 (2004) [Inorg. Mater. 40 (7), 729 (2004)].
B. P. Sobolev, The Rare-Earth Trifluorides, Part 1: The High-Temperature Chemistry of the Rare-Earth Trifluorides (Shubnikov Institute of Crystallography, Russian Academy of Sciences, Moscow, 2000; Institut d’Estudis Catalans, Barcelona, 2000).
J. C. Warf, W. D. Cline, and R. D. Tevebaugh, Anal. Chem. 26(2), 342 (1954).
B. P. Sobolev, Crystallogr. Rep. 47(Suppl. 1), 63 (2002).
V. A. Gorbulev, P. P. Fedorov, and B. P. Sobolev, J. Less-Common Met. 75(1/2), 55 (1980).
U. Klemm and H. A. Klein, Z. Anorg. Allg. Chem. 248(2), 167 (1941).
S. N. Achary, B. R. Ambekar, M. D. Mathews, et al., Thermochim. Acta 320, 239 (1998).
W. H. Zachariasen, Acta Crystallogr. 4(3), 231 (1951).
T. Petzel, V. Marx, and B. Hormann, J. Alloys Compd. 200(1–2), 27 (1993).
V. A. Gorbulev, Candidate’s Dissertation in Chemistry (Institute of Crystallography, USSR Academy of Sciences, Moscow, 1986).
B. P. Sobolev, P. P. Fedorov, D. V. Steinberg, et al., J. Solid State Chem. 17(2), 191 (1976).
B. P. Sobolev and P. P. Fedorov, K. B. Seiranian, and N. L. Tkachenko, J. Solid State Chem. 17(2), 201 (1976).
F. K. Volynets, Opt.-Mekh. Prom-st., No. 9, 48 (1973).
B. P. Sobolev, E. A. Krivandina, I. V. Murin, et al., USSR Inventor’s Certificate No. 311414 (1988).
E. F. Sudakova, E. Ya. Alksnis, R. S. Perlovskii, et al., in Abstracts of Papers of the Symposium on Solid State Ionics, Boston, United States, November 30–December 4, 1992 (Boston, 1992), Section U-6.5, p. 160.
N. I. Sorokin, E. A. Krivandina, Z. I. Zhmurova, et al., in Abstracts of Papers of the All-Russian Conference “Sensor-2000,” St. Petersburg, Russia, June 21–23, 2000 (St. Petersburg, 2000), p. 322.
N. I. Sorokin, E. F. Sudakova, E. A. Krivandina, and B. P. Sobolev, Élektrokhimiya 35(2), 239 (1999) [Russ. J. Electrochem. 35 (2), 223 (1999)].
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Original Russian Text © B.P. Sobolev, I.A. Sviridov, V.I. Fadeeva, S.N. Sul’yanov, N.I. Sorokin, Z.I. Zhmurova, I.I. Khodos, A.S. Avilov, M.A. Zaporozhets, 2008, published in Kristallografiya, 2008, Vol. 53, No. 5, pp. 919–929.
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Sobolev, B.P., Sviridov, I.A., Fadeeva, V.I. et al. Mechanochemical synthesis of nonstoichiometric nanocrystals La1 − y Ca y F3 − y with a tysonite structure and nanoceramic materials from CaF2 and LaF3 crystals. Crystallogr. Rep. 53, 868–880 (2008). https://doi.org/10.1134/S1063774508050234
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DOI: https://doi.org/10.1134/S1063774508050234