Synthesis, crystal structure and physical properties of the TbCo4.5SixLi0.5-x solid solution


  • I. Stetskiv Ivan Franko National University of Lviv
  • V. Kordan Ivan Franko National University of Lviv
  • I. Tarasiuk Ivan Franko National University of Lviv
  • V. Pavlyuk Ivan Franko National University of Lviv



X-ray diffraction, electron microscopy, solid solutions, CaCu5-type structure, electrochemical hydrogenation


Alloys from the region of existence of the solid solution TbCo4.5SixLi0.5-x were synthesized by arc melting. Quantitative and qualitative composition of alloys and powders of electrode materials was determined by scanning electron microscopy and energy-dispersive X-ray spectroscopy. The Tb/Co/Si ratio in the samples was confirmed by X-ray fluorescence spectroscopy. The change in cell parameters within the solid solution existence was established by the results of X-ray powder diffraction (TbCo4.5SixLi0.5-x, x = 0.1–0.4: a = 4.9518(5) – 4.9324(3), c = 3.9727(4) – 3.9746(3) Å). The crystal structure of the solid solution was determined by the Rietveld method (CaCu5 structure type, space group P6/mmm). Cobalt atoms are partially replaced by silicon and lithium only in 2c position. The ability of alloys to reversibly absorb hydrogen was studied by the method of electrochemical hydrogenation. Under experimental conditions the amount of deintercalated hydrogen was about 0.19 H/f.u. The change in cell parameters after hydrogenation (volume increases from 83.74(1) to 85.54(6) Å3) and the stability of the electrode in the electrolyte solution was further confirmed by X-ray phase analysis. Measurements of the electrical resistivity of the samples indicated a decrease of resistivity value with a slight increase in the amount of alkali metal in samples.


M.H. Mintz, I. Javob, D. Shaltiel, L. Schlapbach (Eds.), Hydrogen in Intermetallic Compounds II (Springer, Berlin, 1992).

H.H. Van Mal, K.H.J. Buschow, A.R. Miedema, J. Less. Common. Met. 35(1), 65 (1974);

H.H. Van Mal, K.H.J. Buschow, F.A. Kuijpers, J. Less. Common. Met. 32(2), 289 (1973);

Yu. Liu, H. Yuan, M. Guo, M. Jiang, Int. J. Hydrog. Energy 44, 22064 (2019);

L. Wang, X. Zhang, Sh. Zhou, J. Xu, H. Yan, Qu. Luo, Qi. Li, Int. J. Hydrog. Energy 45, 16677 (2020);

N.O. Chorna, V.M. Kordan, A.M. Mykhailevych, O.Ya. Zelinska, A.V. Zelinskiy, K. Kluziak, R.Ya. Serkiz, V.V. Pavlyuk, Voprosy khimii i khimicheskoi tekhnologii, 2, 139 (2021);

J. Liu, Sh. Zhu, H. Cheng, Zh. Zheng, Zh. Zhu, K. Yan, Sh. Han, J. Alloys Compd. 777, 1087 (2019);

A. Stetskiv, I. Tarasiuk, R. Misztal, V. Pavlyuk, Acta Crystallogr. E 67, 61 (2011);

V. Pavlyuk, W. Ciesielski, N. Pavlyuk, D. Kulawik, M. Szyrej, B. Rozdzynska-Kielbik, V. Kordan, Ionics 25(6), 2701 (2019);

V. Pavlyuk, W. Ciesielski, N. Pavlyuk, D. Kulawik, G. Kowalczyk, A. Balińska, M. Szyrej, B. Rozdzynska-Kielbik, A. Folentarska, V. Kordan, Mater. Chem. Phys. 223, 503 (2019);

K. Dutta, O. N. Srivastava, J. Mater. Sci. 28, 3457 (1993);

A. Percheron-Guégan, C. Lartigue, J. C. Achard, P. Germi, F. Tasset, J. Less. Common. Met. 74(1), 1 (1980);

W. Zhou, Zh. Ma, Ch. Wu, D. Zhu, L. Huang, Yu. Chen, Int. J. Hydrog. Energy 41, 1801 (2016);

A. Stetskiv, B. Rożdżyńska-Kiełbik, G. Kowalczyk, W. Prochwicz, P. Siemion, V. Pavlyuk, Solid State Sci. 38, 35 (2014);

K. Giza, W. Iwasieczko, V. V. Pavlyuk, H. Bala, H. Drulis, J. Power Sources. 181(1), 38 (2008);

J.-M. Joubert, M. Latroche, R. Černý, R. C. Bowman, A. Percheron-Guégan, K. Yvon, J. Alloys. Compd. 293-295, 124 (1999);

F. Meli, A. Zuettel, L. Schlapbach, Z. Phys. Chem. 183(1-2), 371 (1994);

F. Meli, A. Zuettel, L. Schlapbach, J. Alloys. Compd. 190(1), 17 (1992);

MTech. Retrieved from:

W. Kraus, G. Nolze, PowderCell for Windows (Federal Institute for Materials Research and Testing, Berlin, 2000).

V. Petříček, M. Dušek, L. Palatinus, Z. Kristallogr. Cryst. Mater. 229(5), 345 (2014);

D. Schwarzenbach, Program LATCON: refine lattice parameters. (University of Lausanne, Lausanne, 1966).

J. Rodriguez-Carvajal, The Satellite Meeting on Powder Diffraction of the XV Congress of the IUCr (Toulouse, 1990). P. 127.

V. Kordan, I. Tarasiuk, I. Stetskiv, R. Serkiz, V. Pavlyuk, Chem. Met. Alloys. 12(3/4), 77 (2019);

B. Rożdżyńska-Kiełbik, I. Stetskiv, V. Pavlyuk, A. Stetskiv, Solid State Sci. 113, 106552 (2021);

I. Tarasiuk., I. Stetskiv, V. Kordan., V. Pavlyuk, Visn. Lviv Univ. Ser. Chem. 58(1), 117 (2017).



How to Cite

Stetskiv, I., Kordan, V., Tarasiuk, I., & Pavlyuk, V. (2021). Synthesis, crystal structure and physical properties of the TbCo4.5SixLi0.5-x solid solution. Physics and Chemistry of Solid State, 22(3), 577–584.



Scientific articles (Chemistry)