<div class="csl-bib-body">
<div class="csl-entry">Bühler-Paschen, S. (2025, December 2). <i>Understanding the Optical Conductivity of Ce-Based Clathrates and Its Relation to Thermopower</i> [Conference Presentation]. MRS Fall Meeting & Exhibit 2025, Boston, United States of America (the). http://hdl.handle.net/20.500.12708/225037</div>
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dc.identifier.uri
http://hdl.handle.net/20.500.12708/225037
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dc.description.abstract
Cerium-based type-I clathrates exhibit unusual thermoelectric properties, making them promising candidates for energy applications.
The origin of the thermopower enhancement observed at elevated temperatures in CeBa7Au6Si40 remains a subject of active debate, particularly given the coexistence of Kondo scattering and prevailing Curie-Weiss magnetic behavior down to approximately 1 K.
To elucidate the electronic mechanisms contributing to these properties, we compared optical conductivity (sigma(w)) measurements on CeBa7Au6Si40 and its rare-earth-free reference, LaBa7Au6Si40.
Our ab-initio band structure calculations successfully explain sigma(w) for LaBa7Au6Si40. In stark contrast, the optical conductivity of CeBa7Au6Si40 undergoes a significant change near T=100 K, a feature that cannot be explained by conventional band theory, indicating strong 4f-electron correlation effects.
These findings underscore the necessity of a theoretical framework that captures the correlated interplay between 4f-electron physics and the rattling modes of guest atoms.
We propose such an effective model and calculate sigma(w,T), offering a comprehensive understanding of the electronic behavior in these complex materials.
en
dc.language.iso
en
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dc.subject
Clathrates
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dc.subject
Kondo scattering
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dc.subject
Curie-Weiss magnetic behavior
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dc.title
Understanding the Optical Conductivity of Ce-Based Clathrates and Its Relation to Thermopower
