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MA: Fachverband Magnetismus

MA 9: Anisotropy/Magnetoelasticity

MA 9.5: Vortrag

Montag, 26. März 2007, 18:15–18:30, H22

The Magnetoelastic Paradox — •Manuel Zschintzsch¹, Dirk C. Meyer¹, Günter Behr², Jan Prokleska³, Herwig Michor⁴, Mathias Doerr⁵, Michael Loewenhaupt⁵, and Martin Rotter⁶ — ¹ISP, TU Dresden, Germany — ²IFW, Dresden, Germany — ³Charles University, Prague, Czech Republic — ⁴TU-Wien, Austria — ⁵IFP TU-Dresden, Germany — ⁶IPC, Universität Wien, Austria

The Magnetoelastic Paradox [1] describes the difference between the low temperature magnetoelastic behavior of antiferromagnetic compounds and the theoretical predictions due to the spin interactions. While studying the behavior at an atomic scale it’s important to separate the different kinds of interactions, in our case domain effects, single ion contributions and spin interactions.

Accordingly our measurements were performed on antiferromagnetic Gd based compounds: Due to antiferromagnetism domains don’t have to be considered. Additionally Gd exhibits no magnetic orbital momentum. Thus, single-ion contributions to the magnetoelastic behaviour don’t occur. The alloying partners were chosen in a way that they have no, or only weak magnetic moments. All magnetoelastic effects which can be seen from our X-ray diffraction experiments can be attributed to spin interaction of Gd exclusively. We measured the temperature dependend lattice parameters and peakwidths in the temperature range of 15 to 300K. The experimentally determined absence of symmetry breaking distortions (no changes of peakwidth detected) at the Neel-temperature leads to the existence of the magnetoelastic paradoxon.

[1] M. Rotter et al. Europhys. Lett. 75, 160-166 (2006)