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arXiv · 2505.18089

Explaining the extra crystal field mode in ACeX2

Allen O. Scheie·Sabrina J. Li·Stephen D. Wilson·Daniel A. Rehn
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Abstract

A growing list of Ce-based magnets have shown an extra and heretofore unexplained crystal electric field (CEF) mode at high energies. We describe a process whereby an optical phonon can produce a split CEF mode well above the phonon energy. We use density functional theory and point-charge model calculations to estimate the phonon distortions and coupling to model this effect in KCeO$_2$, showing that it accounts for the extra CEF mode observed. This mechanism is generic, and may explain the extra modes observed on a variety of Ce$^{3+}$ compounds.

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Allen O. Scheie, Sabrina J. Li, Stephen D. Wilson, Daniel A. Rehn. 2025-05-23. Explaining the extra crystal field mode in ACeX2. https://doi.org/10.1103/4ps1-y3pk

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