A. Guzik

Magnetotransport properties of the CeCu2Sb2 and CeAg2Sb2 compounds

Abstract The magnetotransport properties of the CeCu 2 Sb 2 and CeAg 2 Sb 2 compounds are presented and discussed. The large negative magnetoresistance, as well as the anomalous Hall effect found for CeAg 2 Sb 2 , are related to the temperature dependence of the susceptibility and magnetic (spin disorder) part of resistivity in this nearly ferromagnetic compound.

Kondo properties of the new compounds Ce(AgxCu1-x)2-δSb2

Abstract Some physical properties of the new compound CeAg2-δSb2 and its solid solutions with CeCu2-δSb2 are reported. All investigated compounds are antiferromagnets. The magnetic structure of CeCu2-δSb2 is frustrated with propagation vector q = (0, 0, 1 2 ) , whereas CeAg2-δSb2 is nonfrustrated with q = (0.06, 0.06, 0).

Electronic structure of the Ce(AgxCu1−x)2Sb2 compounds

Abstract The electronic structure of the Ce(Ag x Cu 1− x ) 2 Sb 2 compounds was investigated by the XPS method. The valence band spectra and electronic states Ag4d, Ag3d, Cu3d, Cu2p, Sb3d are presented. Their fine structure is discussed, based on structure details derived from neutron diffraction data. The location of the lines in the spectra of cerium, copper and silver are shifted to higher binding energy, whereas the lines of antimony are shifted to lower energy. The 3d lines of antimony show a complex structure, which may be related to changes in the valence band caused by the strong chemical bond. The investigation of the Ce 3d states leads to the conclusion that the hybridization energy of the 4f electrons with the conduction electron system varies from 60 meV up to 110 meV in the investigated compounds.

Magnetic structures of Ce(AgxCu1 − x)1.8Sb2 Kondo compounds

Abstract The magnetic structures of the Ce(Ag x Cu 1 − x ) 1.8 Sb 2 compounds have been refined from neutron diffraction. The transition from the CeCu 1.8 Sb 2 commensurate frustrated antiferromagnetic structure to the CeAg 1.8 Sb 2 incommensurate one occurs through ferromagnetic and spin-glass states.

Magnetic and resistivity studies of GdNi2Sn2, GdCu2Sb2 and GdNi2Sb2 compounds

Abstract Ternary GdNi2Sn2, GdCu2Sb2 and GdNi2Sb2 compounds crystallize in the primitive tetragonal CaBe2Ge2-type structure. The compounds investigated are antiferromagnetic below 7 K, 11 K and 6 K respectively. Large negative paramagnetic Curie temperatures accompany these low Neel temperatures. This may be related to the frustration of magnetic interactions. At temperatures lower than TN anomalies in magnetization vs. magnetic field curves and resistivity can be attributed either to a change in magnetic structure or to spin-flopping phenomena.