Dresden 2009 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 43: Correlated Electrons: Heavy Fermions 2
TT 43.2: Vortrag
Donnerstag, 26. März 2009, 16:00–16:15, HSZ 301
Ce and T magnetism in CeTPO compounds (T = Os, Ru, Fe, Co) - Large variety of ground states. — •Cornelius Krellner, Anton Jesche, and Christoph Geibel — Max Planck Institute for Chemical Physics of Solids, Dresden, Germany
In the last years we have started a detailed investigation of the CeTPO compounds (T = Os, Ru, Fe, Co). These materials correspond to the family of LnTPnO systems, crystallizing in the tetragonal ZrCuSiAs structure-type, which attracts a lot of attention due the observation of high temperature superconductivity (SC) in the doped LnFeAsO compounds. Whereas the 3d-magnetism of the Fe is essentially for the occurrence of SC in LnFeAsO, the magnetism in CeTPO is dominated by the 4f-electrons of Ce3+.
In this contribution, we summarize our results on the single crystal growth of the CeTPO materials together with a thorough physical characterization, including magnetization, susceptibility, resistivity, specific heat, and thermopower. These measurements reveal four different magnetic ground states: (1) CeRuPO is a rare example of a ferromagnetically ordered Kondo-lattice system with TC=15 K and a Kondo scale of TK∼10 K; (2) CeOsPO orders antiferromagnetically at TN=4.5 K; (3) CeFePO is a heavy-fermion system on the non-magnetic side of a ferromagnetic instability; (4) CeCoPO present ferromagnetic order of the Co-ions at TC=75 K and Ce-moments close to magnetism. Therefore, these new materials present a nice playground to study in detail the phenomena of strongly correlated electron systems.