Please use this identifier to cite or link to this item: http://dx.doi.org/10.18419/opus-12257
Authors: Trepka, Heiko
Title: Critical magnetic fluctuations in strongly electron-correlated systems
Other Titles: Kritische magnetische Fluktuationen in stark korrelierten Elektronensystemen
Issue Date: 2022
metadata.ubs.publikation.typ: Dissertation
metadata.ubs.publikation.seiten: III, 195
URI: http://nbn-resolving.de/urn:nbn:de:bsz:93-opus-ds-122749
http://elib.uni-stuttgart.de/handle/11682/12274
http://dx.doi.org/10.18419/opus-12257
Abstract: In this work, we use high-resolution neutron Triple-Axis and Spin-echo spectroscopy to study the critical properties of the strongly electron-correlated 4d square-lattice antiferromagnets Ca2RuO4 and Ca3Ru2O7, as well as of the heavy-fermion system CeCu5.8Au0.2 in vicinity and above the Néel-temperatures TN. We extract static and dynamical critical exponents to determine the spin dimensionalities and relevant anisotropies. We find that the critical behaviors of the single-layer compound Ca2RuO4 follow universal scaling laws that are compatible with predictions of the 2D-XY model. The bilayer compound Ca3Ru2O7 is only partly consistent with the 2D-XY theory and best described by the 3D-Ising model, which is likely a consequence of the intra-bilayer exchange interactions in combination with an orthorhombic single-ion anisotropy. For CeCu5.8Au0.2 we find signatures of a quantum-to-classical crossover in the dynamic scaling behavior.
Appears in Collections:08 Fakultät Mathematik und Physik

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