Synthesis of sulfide mineral crystals by incongruent methods using the example of Cu-Fe-S and Cu-Fe-Se systems

Research subject. Understanding the structure and thermodynamic properties of sulfide minerals is important for studying the paragenesis of sulfide formation on Earth and in space, as well as for analyzing technological issues in the processing of ores and polysulfide product concentrates. There is a lack of experimental and theoretical information on many representatives of the Cu-Fe-S and Cu-Fe-Se systems. Aim. To synthesize crystals in the Cu-Fe-S and Cu-Fe-Se systems at the lowest possible temperatures for the subsequent study of their physical properties, while solving the main problem of materials science related to interrelations between composition, structure, and properties. Materials and methods. Crystal synthesis was carried out by the solution-melt method in a stationary temperature gradient, in evacuated sealed quartz glass ampoules. Two types of ampoules were used in the experiment, standard and long. The ampoules were filled with a charge and a salt mixture of RbCl-LiCl of eutectic composition, evacuated and sealed, then placed in several quartz or ceramic glasses. The glasses were placed in tubular furnaces such that the ends of the ampoules with the charge were located closer to the center of the furnace, and the opposite ends were closer to the edge to create a temperature gradient. For standard ampoules, the hot end temperature was 520–469℃, and the cold end was 456–415℃. For long ones: 470℃ – hot end and 340℃ – cold. The synthesis duration ranged from three to four months. Results. Depending on the composition of the charge, crystals of chalcocine Cu₂S, bornite Cu₅FeS₄, chalcopyrite CuFeS₂, isocubanite CuFe₂S₃, and iron-containing dicopper sulfide with an iron content of up to 8 at % and various equilibrium associations with their participation and with the participation of pyrite FeS₂ and pyrrhotites Fe_1–xS were obtained. Copper dendrites were also found in some samples. In addition, crystals of a phase with the approximate composition of CuFeSe2 were obtained. It is shown that due to different combinations of oxidation states of all three elements dissolved in a salt electrolyte, it is possible to obtain phases with almost any stoichiometric ratio. Chalcopyrite and isocubanite are reliably detected using Raman spectroscopy. In this case, some samples are locally characterized by the “absence” of a spectrum, which probably indicates the metallic (semi-metallic) properties of the samples. Conclusion. Using the Cu-Fe-S and Cu-Fe-Se systems as an example, the possibility of obtaining sulfide crystals in a RbCl-LiCl salt melt up to a eutectic temperature of 313℃ is shown. Due to the low synthesis temperature, the synthesis should be carried out over several months, resulting in crystals a fraction of a millimeter in size.

1. Bernardini G.P., Corsini F., Mazzetti G., Trosti-Ferroni R. (1982) Phase relations in the CuFeSe system at 300°C. Mat. Res. Bull., 17(8), 981-991.

2. Böhmer A.E., Taufour V., Straszheim W.E., Wolf T., Can-field P.C. (2016) Variation of transition temperatures and residual resistivity ratio in vapor-grown FeSe. Phys. Rev. B, 94(2), 024526.

3. Chandra U., Singh N., Sharma P., Parthasarathy G. (2011) High‐Pressure Studies on Synthetic Orthorhombic Cubanite (CuFe2S3). AIP Conf. Proceed. Amer. Inst. Phys., 1349(1), 143-144.

4. Chareev D.A., Volkova O.S., Geringer N.V., Evstigneeva P.V., Zgurskiy N.A., Koshelev A.V., Nekrasov A.N., Osadchii V.O., Filimonova O.N. (2019) The Synthesis of Crystals of Chalcogenides of K, Zr, Hf, Hg, and Some Other Elements in Halide Melts under Conditions of Stationary Temperature Gradient. Cryst. Rep., 64, 996-1002.

5. Chareev D.A. (2016) General principles of the synthesis of chalcogenides and pnictides in salt melts using a steady-state temperature gradient. Cryst. Rep., 61(3), 506-511.

6. Chareev D.A., Volkova O.S., Geringer N.V., Koshelev A.V., Nekrasov A.N., Osadchii V.O., Osadchii E.G., Filimonova O.N. (2016) Synthesis of chalcogenides and pnictides in salt melts using a steady-state temperature gradient. Cryst. Rep., 61(4), 682-691.

7. Feiguin A.E. et al. (2019) Quantum liquid with strong orbital fluctuations: the case of a pyroxene family. Phys. Rev. Lett., 123(23), 237204.

8. Greenwood N.N., Whitfield H.J. (1968) Mössbauer effect studies on cubanite (CuFe2S3) and related iron sulphides. J. Chem. Soc. A: Inorgan., Phys., Theor., 1697-1699.

9. Hamdadou N. et al. (2006) Fabrication of n-and p-type doped CuFeSe2 thin films achieved by selenization of metal precursors. J. Phys. D: Appl. Phys., 39(6), 1042.

10. Imbert P., Wintenberger M. (1967) Étude des propriétés magnétiques et des spectres d'absorption par effet Mössbauer de la cubanite et de la sternbergite. Bulletin de Minéralogie, 90(3), 299-303.

11. Iordanidis A., Garcia-Guinea J., Strati A., Gkimourtzina A. (2013) Gold gilding and pigment identification on a post-byzantine icon from Kastoria, Northern Greece. Analyt. Lett., 46(6), 936-945.

12. Jackeli G., Khaliullin G. (2009) Magnetically Hidden Order of Kramers Doublets in d 1 Systems: Sr2VO4. Phys. Rev. Lett., 103(6), 067205.

13. Jaimes E., Gonzalez-Jimenez F., D’Onofrio L., Iraldi R., Quintero M., Gonzalez J. et al. (1994) Evidence for the existence of two electronic states in the chalcopyrite-type alloys CuFe(S1−zSez)2. Hyperfine Interact., 91, 607-612.

14. Khomskii D.I., Streltsov S.V. (2020) Orbital effects in solids: Basics, recent progress, and opportunities. Chem. Rev., 121(5), 2992-3030.

15. Liu H., Khaliullin G. (2018) Pseudospin exchange interactions in d 7 cobalt compounds: Possible realization of the Kitaev model. Phys. Rev. B., 97(1), 014407.

16. Ma M., Ruan B., Zhou M., Gu Y., Dong Q., Yang Q., Wang Q., Chen L, Shi Y., Yi J., Chen J., Ren Z. (2023) Growth of millimeter-sized high-quality CuFeSe2 single crystals by the molten salt method and study of their semiconducting behavior. J. Cryst. Growth, 622, 127398.

17. Makovicky E., Karup-Møller S. (2020) The central portions of the Cu-Fe-Se phase system at temperatures from 900 to 300°C. Canad. Miner., 58(2), 203-221.

18. Merwin H.E., Lombard R.H. (1937) The system Cu-Fe-S. Econ. Geol., 32(2_Suppl), 203-284.

19. Mikuła A., Koleżyński A. (2019) First principles studies of Fe-doped Cu2S–Theoretical investigation. Solid State Ionics, 334, 36-42.

20. Pankrushina E.A., Votyakov S.L., Aksenov S.M., Komleva E.V., Uporova N.S., Vaitieva Y.A. (2023) In situ thermo‐Raman spectroscopy and ab initio vibrational assignment calculations of cubanite CuFe2S3. Raman Spectrosc., 54(7), 769.

21. Pankrushina E.A., Ushakov A.V., Abd-Elmeguid M.M., Streltsov S.V. (2022) Orbital-selective behavior in cubanite CuFe2S3. Phys. Rev. B, 105(2), 024406.

22. Parker G.K., Woods R., Hope G.A. (2008) Raman investigation of chalcopyrite oxidation. Coll. Surf. A: Physicochem., Eng. Aspects, 318(1-3), 160-168.

23. Polubotko A.M. (2011) Ferron-type conductivity in metallic CuFeSe2. The Phys. Metals Metallogr., 112, 589-590.

24. Pruseth K.L., Mishra B., Bernhardt H.-J. (1999) An experimental study on cubanite irreversibility: implications for natural chalcopyrite-cubanite intergrowths. Eur. J. Mineral., 11(47), 471-476.

25. Schafer H. (1962) Chemische Transportreaktionen.Weinhelm; Bergstr: Verlag Chemie, MnbH, 190 p.

26. Sleight A.W., Gillson J.L. (1973) Electrical resistivity of cubanite: CuFe2S3. J. Solid State Chem., 8(1), 29-30.

27. Solache-Carranco H. et al. (2009) Photoluminescence and X-ray diffraction studies on Cu2O. J. Luminesc., 129(12), 1483-1487.

28. Springer Materials Database: https://materials.springer.com

29. Timofeeva V.A. (1978) Crystal Growth from Flux. Moscow, Nauka Publ., 266 p. (In Russ.)

30. Vilke K.-T. (1977) Crystal Growth. (Eds T.G. Petrov and O.Yu. Punin). Leningrad, Nedra Publ., 600 p. (In Russ.)