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P. Rogl, E. Bauer, G. Hilscher, H. Kaldarar, E. Royanian, H. Michor, E. Scheidt, A. Gribanov, Y. Seropegin:
"Novel Compounds RE{Ir,Pd,Pt}₂Si - Structure and Properties";
Vortrag: International Workshop on Exotic States in Materials with Strongly Correlated Electrons, Sinaia, Romania; 07.09.2007 - 10.09.2007.

Abstract:
Compounds {La,Ce}{Ir,Pt}₂Si and {Yb,Lu}{Pd,Pt}₂Si have been synthesized by arc melting. Whereas {La,Ce}Pt₂Si crystallize in the inverse CeNiSi₂-type structure, CeIr₂Si adopts a modified unique structure type. The compounds {Yb,Lu}{Pd,Pt}₂Si crystallize in the ordered Fe₃C-structure. Magnetic properties are dominated by a mutual interaction of the RKKY interaction, the Kondo effect and crystal electric field splitting, resulting for CePt₂Si in long range magnetic order below about 7 K. A slightly enhanced Sommerfeld value γ= 42 mJ/molK₂ and a distinct temperature dependence of the electrical resistivity refers to Kondo interaction in presence of strong crystal electric field splitting. YbPd₂Si is characterised by Kondo lattice features at higher temperatures and, presumably, antiferromagnetism at 2.1 K. A quasiquartet crystal field ground state governs the physics at low temperature. The most important observation is that in the case of YbPt₂Si there are well separated CEF levels, while in YbPd2Si, the first excited CEF level is only about 12 K above the ground state. Such a feature is very rare to be observed.