High-permeability films of CoNiFe triple system form the basis for high-density magnetic data storage. Electrochemical deposition of CoNiFe films, as contrasted with «dry» processes, gives more homogeneous coating with lesser defect level and allows reinforcing the films thickness without stresses. This study investigates the nature of the phenomena taking place at electrochemical deposition of CoNiFe films and leading to the difference in the relative content of the elements in the electrolyte and in the film. The hydrogen exponent of chloride electrolytes was examined in the temperature range of 25-70 °C and electrochemical deposition of CoNiFe films at 70 °C was studied. It was demonstrated that CoCl, NiCl, FeCl salt solutions with concentration from 0,006 to 1 mole/l are characterized by complex process of ion balance formation in single and mixed solutions. The deposition of CoNiFe films was carried out from chloride electrolyte with a component content ratio of 1:1:1 at an average concentration of 0,083 mole/l of each component. It has been established that the content of the component in the film at electrochemical deposition of three-component solution CoCl, NiCl, FeCl with equal concentration of each component did not correspond to the composition of the electrolyte but was closest to the composition of the electrolyte at a decrease in the concentration of each component at high current density.
1. Tabakovic I., Venkatasamy V. Preparation of metastable CoFeNi alloys with ultra-high magnetic saturation (Bs = 2.4–2.59 T) by reverse pulse electrodeposition // J. of Magn. and Magn. Mat. 2018. Vol. 452. P. 306–314. DOI: https://doi.org/10.1016/j.jmmm.2017.12.003
2. Electroplated Fe-Co-Ni films prepared in ammonium-chloride-based plating baths / T. Yanai, K. Koda, J. Kaji et al. // AIP Advances. 2018. Vol. 8. Iss. 5. P. 056127. DOI: https://doi.org/10.1063/1.5007782
3. Romankov S., Park Y.C., Shchetinin I.V. Mechanical intermixing of elements and self-organization of (FeNi) and (CoFeNi) nanostructured composite layers on a Ti sheet under ball collisions // J. of Alloys and Comp. 2015. Vol. 653. P. 175–186. DOI: https://doi.org/10.1016/j.jallcom.2015.08.269
4. Li D., Podlaha E. Template-assisted electrodeposition of Fe-Ni-Co nanowires: Effects of electrolyte pH and sodium lauryl sulfate // J. Electrochem. Soc. 2017. Vol. 164 (13). P. D843–D851. DOI: https://doi.org/10.1149/2.0931713jes
5. Yang Y. Preparation of Fe-Co-Ni ternary alloys with electrodeposition // Int. J. Electrochem. Sci. 2015. Vol. 10. Issue 6. P. 5164–5175.
6. Коровин Н.В. О катодном процессе при электроосаждении сплава железо-никель // Журнал неорганической химии. 1957. Т. 2. № 9. С. 2259–2263.
7. Mechanism of anomalous type electrodeposition of Fe-Ni alloys from sulfate solutions / H. Nakano, M. Matsuno, S. Oue et al. // Mater. Trans. 2004. Vol. 45. No. 11. P. 3130–3135.
8. Microstructure and tribological properties of electrodeposited Ni–Co alloy deposits / L. Wang, Y. Gao, Q. Xue et al. // Appl. Surf. Sci. 2005. Vol. 242 (3-4). P. 326–332. DOI: https://doi.org/10.1016/j.apsusc.2004.08.033
9. The influence of saccharin on the electrodeposition and properties of Co–Ni alloy thin films / S. Tebbakh, Y. Messaoudi, A. Azizi et al. // Transactions of the IMF – The International Journal of Surface Engineering and Coatings. 2015. Vol. 93 (4). P. 196–204. DOI: https://doi.org/10.1179/0020296715Z.000000000247
10. Preparation, structure and giant magnetoresistance of electrodeposited Fe-Co/Cu multilayers / В.G. Tóth, L. Péter, L. Pogány et al. // J. Electrochem. Soc. 2014. Vol. 161 (4). P. D154–D162. DOI: https://doi.org/10.1149/2.053404jes
11. Tikhonov R. Congruent electrochemical deposition of NiFe alloy: The results of the research. Beau Bassin: Lambert Academic Publishing, 2019. 204 p.
12. Тихонов Р.Д. Электрохимическое осаждение сплава NiFe при температуре 70 ºС // Электрохимия. 2020. Т. 56. № 7. С. 666–669. DOI: https://doi.org/10.31857/S0424857020070063
13. Тихонов Р.Д., Черемисинов А.А., Горелов Д.В., Казаков Ю.В. Магнитные свойства пленок Co-Ni-Fe, полученных электрохимическим осаждением по методу Тихонова // Нано- и микросистемная техника. 2020. Т. 22. № 3. С. 123–135. DOI: https://doi.org/10.17587/nmst.22.123-135
14. Lee M.-S. Use of the bromley equation for the analysis of ionic equilibria in mixed ferric and ferrous chloride solutions at 25 °C // Metallurgical and Materials Transactions B. 2006. Vol. 37 (2). P. 173–179. DOI: https://doi.org/10.1007/BF02693146
15. Lee M.-S., Oh Y.-J. Chemical equilibria in a mixed solution of nickel and cobalt chloride // Mater. Trans. 2005. Vol. 46 (1). P. 59–63. DOI: https://doi.org/10.2320/matertrans.46.59