ELECTROCHEMICAL SYNTHESIS OF ULTRAFINE INTERMETALLIC POWDERS BASED ON LANTHANUM AND COBALT FROM CHLORIDE MELTS
https://doi.org/10.17073/1997-308X-2017-2-4-13
Abstract
The paper studies the combined electroreduction of lanthanum LaCl63–and cobalt CoCl42– chloride complexes in an equimolar KCl–NaCl melt at a tungsten electrode. As it follows from the results of voltampere measurements, potentials of La and Co reduction at a tungsten electrode coated with preliminary reduced cobalt differ by more than 1,0 V. Therefore, the electrochemical synthesis of La and Co intermetallics is possible only in the kinetic regime. The paper develops the method for the high-temperature electrochemical synthesis of lanthanum and cobalt intermetallic powders in halide melts. The paper determines conditions for realization of the combined electroreduction of La3+ and Co2+ ions, on the basis of which the paper demonstrates the principal possibility of the direct electrochemical synthesis of lanthanum intermetallics. The paper establishes that the electrosynthesis mechanism is determined by electrolysis conditions. Under potentiostatic conditions (when potentials are more negative than potentials for reduction of the more electronegative element – lanthanum) the combined reduction of La and Co takes place, and the synthesis process is determined by the activation energy of the interaction reaction between lanthanum and cobalt at the cathode. In general, the electrosynthesis of La- and Co-based intermetallics is determined by the following interrelating parameters – the composition of the electrolytic bath and the voltage across it. The paper describes the high-temperature electrochemical synthesis of lanthanum- and cobalt-based ultrafine powders of intermetallics кобальта (Сo3La2, Сo7La2, Co13La) from chloride melts.
About the Authors
Kh. B. KushkhovRussian Federation
Dr. Sci. (Chem.), Prof., Head of the Department of inorganic and physical chemistry
(360004, Russia, Nalchik, Chernyshevsky str., 173)
M. K. Vindizheva
Russian Federation
Cand. Sci. (Chem.), Associate professor of the Department of inorganic and physical chemistry
R. A. Mukozheva
Russian Federation
Graduate student of the Department of inorganic and physical chemistry
M. N. Kalibatova
Russian Federation
Cand. Sci. (Chem.), Associate professor of the Department of inorganic and physical chemistry
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Review
For citations:
Kushkhov Kh.B., Vindizheva M.K., Mukozheva R.A., Kalibatova M.N. ELECTROCHEMICAL SYNTHESIS OF ULTRAFINE INTERMETALLIC POWDERS BASED ON LANTHANUM AND COBALT FROM CHLORIDE MELTS. Powder Metallurgy аnd Functional Coatings (Izvestiya Vuzov. Poroshkovaya Metallurgiya i Funktsional'nye Pokrytiya). 2017;(2):4-13. (In Russ.) https://doi.org/10.17073/1997-308X-2017-2-4-13