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 |
Files in This Item:
File | Description | Size | Format | |
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PHD_thesis_HeikoTrepka.pdf | 30,55 MB | Adobe PDF | View/Open |
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