Zelinska O. Interaction of zinc with rare earths (La, Ce, Sm, Gd, Tb) and cobalt: phase equilibria, crystal structure of the compounds and some physical properties

The thesis is devoted to the investigation of the components interaction in the {La, Ce, Sm, Gd, Tb}-Со-Zn ternary systems. The isothermal sections of the phase diagrams at 470 K over the whole concentration range were constructed by X-ray phase, local X-ray depressive analyses and differential scanning calorimetry. The existence of 2 ternary compounds with CeCr2Al20 structure type was confirmed. The existence of 28 new ternary compounds was found and their crystal structure was determined. The crystal structures of the compounds belong to 9 structure types; one from them ErCuCd2 is new. The homogeneity regions are determined for 7 ternary compounds and for the solid solutions on the basis of a number of binary compounds. Dependences of the magnetization from the magnetic field and temperature for the SmCo4,4Zn0,6 and SmCo3,2-3,5Zn1,8-1,5 ternary compounds were investigated. These compounds show ferromagnetic properties. The direction of the light magnetization axis for the SmCo4,4Zn0,6 compound was investigated. It coincides with the crystallographic direction 00l. The electrochemical hydrogenation of the alloys from homogeneity range of the LaCo4,4Zn0,6 ternary compound and solid solutions LaNi5-xZnx and SmNi5-xZnx was carried out. These alloys are characterized by high absorbing capacity and would be using as anode materials in the metal hydride current sources. The current sources with specific energy of 50-100 W·h/kg would be originated depending on the composition.