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

Abstract

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 3d512 and 3d3/2 are equal to 18.8 eV for R = Ce, 20.2 eV for R = Pr and 22.6 eV 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.

Magnetic, electronic and transport properties of the Ce3Ag4X4 (X=Ge, Sn) compounds

“…The analysis of the f 2 weight in the Ce 3d XPS spectra performed on the basis of the Gunnarsson-Schönhammer theory suggested a hybridization strength of 169 meV for Ce 3 Ag 4 Ge 4 and 82 meV for Ce 3 Ag 4 Sn 4 . The value estimated for the germanide is similar to those determined for CeAgSn (165 meV) [21] and CeRhSb (140 meV) [22], and indicates rather strong hybridization of the 4f electrons with the conduction band electrons. In turn, the value derived for Ce 3 Ag 4 Sn 4 indicates noticeably weaker hybridization.…”

Review on magnetic and related properties of RTX compounds

“…XPS valence bands for RAgSn (R=Ce, Pr, Nd, Dy) are compared with those calculated using spin polarized tight binding linear muffin tin orbital method. This reveals that the valence bands are mainly determined by Ag 4d band [529]. The electronic structure studied by XPS and ab initio calculations shows that valence bands in LaPtIn and CePtIn are dominated by the Pt 5d and In 5s and 5p states [530].…”

Magnetic and Electrical Behavior in CeMgGa

“…Equiatomic cerium intermetallics CeTX (T = transition metal, X = element of the 3rd, 4th, or 5th maingroup) have attracted considerable interest in recent years with respect to their largely varying magnetic and electrical properties. − Prominent examples are the Kondo systems CeAuAl, CeNiSn and CeRhSb, the metamagnet CePtAs, mixed-valent CeIrAl 44 and CeNiAl 39 , or the ferromagnets CeAgGa 28 and CeAuGe .…”