Regensburg 2019 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 50: Poster Session: Correlated Electrons 2

TT 50.21: Poster

Mittwoch, 3. April 2019, 15:00–18:30, Poster D

Investigation of the magnetic interactions in the tripod-Kagome compound Mg₂Gd₃Sb₃O₁₄ by electron spin resonance experiments — •Christoph Wellm^1,2, Julian Zeisner^1,2, Mihai Sturza¹, Gaël Bastien^1,2, Sebastian Gaß¹, Anja U.B. Wolter¹, Bernd Büchner^1,2, and Vladislav Kataev¹ — ¹Leibniz Institute for Solid State and Materials Research IFW Dresden, D-01171 — ²Institut für Festkörper-und Materialphysik, TU Dresden, D-01062

As an example of a class of geometrically frustrated magnetic systems, the so-called tripod Kagome materials have been suggested as an interesting target of experimental investigation due to the frustrated nature and the question of dimensionality of the magnetic interactions. In our work we performed high-field electron spin resonance measurements on a powder sample of Mg₂Gd₃Sb₃O₁₄, a representative of a quasiclassical Heisenberg magnet, where the effect of spin-orbit coupling of Gd³⁺ ions vanishes to first order. Measurements were conducted over a frequency range of 70-420 GHz and temperatures ranging from 3-50 K. The Gaussian lineshape is consistent with a model of dominant dipolar spin-spin interactions, while the growing asymmetry of the lineshape upon decrease of temperature signifies an increase of an effective internal field, an indication of increasing short-range spin-spin-correlations. Such a behavior is typical for frustrated systems, making our studies one of the first to reveal such significant features in this family of materials. Furthermore, temperature dependent critical broadening of the linewidth and increase of the internal field strength provide insights into the dimensionality of the spin-spin correlations.