Dresden 2009 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 16: Correlated Electrons: Low-dimensional Systems - Materials 1

TT 16.2: Vortrag

Dienstag, 24. März 2009, 09:45–10:00, HSZ 304

Electron Spin Resonance in GdI₂H_x — •Georg Andreas Hilscher¹, Joachim Deisenhofer¹, Hans-Albrecht Krug von Nidda¹, Alois Loidl¹, Mikhail Ryazanov², Arndt Simon², and Reinhard K. Kremer² — ¹Experimentalphysik V, Elektronische Korrelationen und Magnetismus, Universität Augsburg, 86135 Augsburg, Germany — ²Max-Planck Institut für Festkörperforschung, Heisenbergstraße 1, 70569 Stuttgart, Germany

The spin dynamics of hydrogen-doped GdI₂H_x (0 ≤ x ≤ 1) have been investigated by electron spin resonance (ESR) spectroscopy. With rising hydrogen concentration the lattice constants of the hexagonal layered structure change: a decreases and c increases [1]. Furthermore, the ferromagnetic Curie temperature T_C, which for pristine GdI₂ lies at approximately 290 K, decreases and the system exhibits a spin-glass-like state for x > 0.33. For higher H concentrations the system remains paramagnetic down to 4 K [1]. From the ESR intensity we can estimate the dominant exchange coupling constant within the Gd layers for x < 0.33 using the model for the spin susceptibility proposed by Eremin et al. [2].

[1] M. Ryazanov, A. Simon, R. K. Kremer, H. Mattausch, Sol. State Chem. 178, 2339 (2005).

[2] I. Eremin, P. Thalmeier, P. Fulde, R. K. Kremer, K. Ahn, A. Simon, Phys. Rev. B 64, 064425 (2001).