Dresden 2011 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 44: Poster Session Correlated Electrons

TT 44.9: Poster

Donnerstag, 17. März 2011, 10:00–13:00, P1

CeCo(As/P)O pnictides: complex interplay of 4f and 3d magnetism as seen from NMR (³¹P, ⁵⁹Co and ⁷⁵As). — •Michael Baenitz¹, Rajib Sarkar¹, Eva Brünining¹, Asok Poddar², Chandan Majumdar², Anton Jesche¹, Cornelius Krellner¹, Cristoph Geibel¹, and Frank Steglich¹ — ¹MPI for Chemical Physics of Solids, 01187 Dresden, Germany — ²ECMP Division, Saha Institute of Nuclear Physics, Kolkata, India

The coupling of the magnetic sub-systems of Co-3d and Ce-4f ions in the compounds CeCoAsO and CeCoPO is studied by using the local NMR probe. The magnetic order in such 3d-4f systems is rather complex depending on the inter-3d, inter-4f ion exchange coupling and the intra 3d-4f - ion coupling (polarization). Sometimes two separated transitions could be found (for example CeFeAsO). For CeCo(P/As)O only a single ferromagnetic transition is found at about 75 K [1,2]. Here CeCoPO is of special interest because strong correlations (Kondo interaction) became evident at low temperatures [2]. Furthermore, recent low field magnetization results indicate a more complex type of magnetic order. One scenario is a crossover from a canted or antiferromagnetic type at low fields to a field polarized ferromagnetic type of order at higher fields.
Phys. Rev. B 82, 054423 (2010)
Physica B, 404 (2009) 3206.