Berlin 2005 – wissenschaftliches Programm
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MA: Magnetismus
MA 20: Poster:Schichten(1-29),Spintrsp(30-45),Ex-Bias(46-63),Spindyn(64-75),Mikromat.(76-80),Cluster(81-94),Abbv.(95-99),Obflm(100-02),SpElek.(103-09),E-Theo(110-14),Mikromag.(115-16),Spin+PÜ(117-26),Mag.Mat.(127-51),Meth.(152-55),Mol.Mag(156-59),Kondo(160-65
MA 20.161: Poster
Montag, 7. März 2005, 14:00–18:00, Poster TU C
EuGe: A system close to the transition from a ferro- to an antiferromagnetic state — •Julia Ferstl and Christoph Geibel — Max Planck Institut fuer Chemische Physik fester Stoffe, Noethnitzer Strasse: 40, 01187 Dresden
The Rare earth compound series RGe has attracted some attention because of the transition from a ferromagnetic state for light rare earth towards an antiferromagnetic state for heavy rare earth, the transition occurring in between Nd and Eu. However, for EuGe, beside structural data, only the susceptibility and a magnetization curve at low T have yet been reported [1]. From these data a divalent Eu state ordering antiferromagnetically below TN = 20 K was inferred. In an attempt to synthesize EuFe2Ge2, we obtained EuGe single crystals. We present here the investigation of these single crystals by means of susceptibility, specific heat and resistivity measurements. Our results confirm a divalent Eu state, but indicate a more complex magnetic ordering behavior. Very pronounced anomalies in the specific heat and in the resistivity show that magnetic ordering occurs at a much higher temperature TN = 38 K, while a pronounced anomaly in the susceptibility in low fields at 25 K, which likely corresponds to the anomaly seen in [1], indicate a further transition associated with a change in the magnetic structure. This complex magnetic behavior is probably related to the proximity to a ferromagnetic state, which is also evidenced by a ferromagnetic Curie-Weiss temperature θ CW = + 34 K. [1] K.H.J. Buschow et al. Journal of Less-Common Metals, 139 (1988) 221-231