Dresden 2011 – scientific programme
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TT: Fachverband Tiefe Temperaturen
TT 49: CE: Spin Systems and Itinerant Magnets 2
TT 49.11: Talk
Thursday, March 17, 2011, 16:45–17:00, HSZ 03
Magnetic and structural properties of AFe4X2 (A = Y, Sc, Lu, and Zr; X = Ge and Si) — •Nandang Mufti1, Til Dellmann2, Philipp Materne2, Hans H. Klauß2, Graeme Blake3, Thomas T. M. Palstra3, and Christoph Geibel1 — 1MPI für Chemische Physik fester Stoffe, Dresden, Germany — 2Institut für Festkörperphysik, TU Dresden, Dresden, Germany — 3Zernike Institute for Advanced Materials, University of Groningen, Groningen, The Netherlands
The compound RFe4Ge2 (R = Dy, Ho, Er, Y) have been reported to crystallize with the tetragonal ZrFe4Si2 structure type and to show interesting magnetic properties. In YFe4Ge2, antiferromagnetic ordering with small ordered moment ∼ 0.63 µB occurs simultaneously with a large (2.5 %) first order structural distortion from tetragonal to orthorhombic at 43.5 K. The presence of a large structural distortion despite a weak antiferromagnetic ordering with low TN and small moments is reminiscent of observations in Fe-arsenides. Here, we will present magnetic and structural properties of AFe4X2 (A = Y, Sc, Lu and Zr; X = Ge and Si) based on magnetic susceptibility, specific heat, resistivity and low temperature X-ray diffractometer measurements. Our results indicate the occurrence of a transition in all compounds at critical temperatures between 30 K and 75 K depending on the compounds. There is no systematic relationship between TN and and the lattice parameters of AFe4X2. However, magnetic order and structural distortion seems generally to be connected. The relation between structural, electronic, and magnetic properties will be discussed.