Berlin 2015 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 67: Correlated Electrons: f-Electron Systems

TT 67.9: Vortrag

Mittwoch, 18. März 2015, 17:15–17:30, H 3005

Ambient pressure superconductivity emerging in the antiferromagnetic phases of the novel heavy fermion compounds Ce₃PdIn₁₁ and Ce₃PtIn₁₁ — •Marie Kratochvílová, Jan Prokleška, Klára Uhlířová, Vladimír Sechovský, and Jeroen Custers — Department of Condensed Matter Physics, Charles University, Prague, Ke Karlovu 5, 121 16, Czech Republic

Ce_nT_mIn_3n+2m (n=1,2; m=1; T=transition metal) heavy fermion compounds are known to be on the verge of a magnetic to non-magnetic quantum critical point (QCP). In close vicinity of the QCP they exhibit an unconventional superconducting state. However, this family of compounds is interesting for an other reason. The compounds crystallize in the tetragonal structures which provide the possibility to tune the structural dimensionality from more 2D to 3D (stoichiometries: 115-218-103). This makes them ideal candidates to investigate the influence of the parameter dimensionality with respect to quantum criticality.

Ce₃TIn₁₁ (T=Pd,Pt) single crystals were prepared for the first time. Ce₃PtIn₁₁ (Ce₃PdIn₁₁) exhibits two successive transitions at T₁=2.2K (T₁=1.7K) and T_N=2.0K (T_N =1.5K) into incommensurate and commensurate local moment antiferromagnetic states, respectively. Applying magnetic field along the c-axis gradually suppresses both transitions; they merge at 4T and split again in higher fields. Superconductivity emerges at T_C=0.32K (T_C=0.39K) and it is enhanced by the application of hydrostatic pressure. The unusual magnetic phase diagram will be discussed in the context of superconductivity and magnetism in related compounds.