Romaniv I. The {Sm, Ho}-{Ni, Ag}-Sn ternary systems: crystal, electronic structures and some physical properties of ternary stannides

The experimental results of the study of the interaction between the components in the {Sm, Ho}{Ni, Ag}Sn ternary systems, crystal and electronic structures, magnetic and electrical properties of the ternary stannides are presented in the work. Isothermal sections of the phase diagrams of the ternary systems Sm-Ni-Sn at 773 K, Ho-Ni-Sn at 673 and 873 K, Sm-Ag-Sn at 873 K and Ho-Ag-Sn at 673 and 873 K over the whole concentration range were constructed for the first time. The limits of existence of the seven solid solutions were established. Formation of seven new ternary stannides were found and their structural characteristics were studied. The electrical and magnetic properties for four series of isostructural compounds and electrical properties for R3Ag4Sn4 stannides have been studied. It was found that all investigated compounds in which rare earth atoms have a localized magnetic moment, are Curie Weiss paramagnets above 80 K. Lu and Y compounds are Pauli paramagnets, while Sm3Ni8Sn4 exhibits a weak paramagnetism. According to electrical property measurements a metallic type of conductivity for all the studied compounds was established. The correlation between the magnetic and electrical properties of the compounds was analyzed. The behavior of the electrical properties was confirmed by calculation of electron density state distribution (DOS). The influence of the nature of the f- and d-elements in the {Sm, Ho} {Ni, Ag} Sn systems on the phase equilibria, stoichiometry, the number of formed compounds and their chemical bonding are analyzed. It has been established that electron filling of the d-level of transition elements (Ni, Ag) or the f-level of the rare earth metals (Sm, Ho) affects the nature of the component interaction, the number of formed ternary compounds and their crystal structures.