Electronic and Transport Properties of Ragsn (R=Ce,Pr,Nd,Dy) Compounds

D. Fusa, V. Ivanovb, A. Jezierskic, B. Penca and A. Szytułaa aInstitute of Physics, Jagiellonian University, Reymonta 4, 30-059 Kraków, Poland bGeneral Physics Institute, Academy of Sciences, 117742 Moscow, Russia cInstitute of Molecular Physics, Polish Academy of Sciences Smoluchowskiego 17, 60-179 Poznań, Poland

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The electronic structure of the ternary RAgSn (R=Ce,Pr,Nd,Dy) compounds which crystallize in the hexagonal LiGaGe-type structure was studied by X-ray photoemission spectroscopy. Core-levels and valence bands were investigated. The X-ray photoemission spectroscopy valence bands are compared with the ones calculated using the spin-polarized tight-binding linear muffin-tin orbital method. The obtained results indicate that the valence bands are mainly determined by the Ag 4d band. The spin-orbit splitting values ΔSO determined from the XPS spectra of 3d5/2 and 3d3/2 are equal to 18.8eV for R= Ce, 20.2eV for R = Pr and 22.6eV for R = Nd. The analysis of these spectra on the basis of the Gunnarsson-Schönhammer model gives a hybridization of f orbitals with the conduction band. The calculation of the total energy for two models of the crystal structure: an ordered of the LiGaGe-type and a disordered one of the CaIn2-type indicate that in these compounds the LiGaGe-type structure is stable. Additionally, the temperature dependences of the electrical resistivity of CeAgSn and DyAgSn are investigated. At high temperatures the resistivity is not a linear function of temperature which indicates an electron-phonon interaction in the presence of a small s-d scattering, whereas at low temperatures anomalies connected with the magnetic phase transitions are observed.

DOI: 10.12693/APhysPolA.98.571 PACS numbers: 71.20.-b, 72.15.Eb, 79.60.-i