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arXiv · 0710.2778

Determining the crystal-field ground state in rare earth Heavy Fermion materials using soft-x-ray absorption spectroscopy

P. Hansmann·A. Severing·Z. Hu·M. W. Haverkort·C. F. Chang·S. Klein·A. Tanaka·H. H. Hsieh·H. -J. Lin·C. T. Chen·B. Fåk·P. Lejay·L. H. Tjeng
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Abstract

We infer that soft-x-ray absorption spectroscopy is a versatile method for the determination of the crystal-field ground state symmetry of rare earth Heavy Fermion systems, complementing neutron scattering. Using realistic and universal parameters, we provide a theoretical mapping between the polarization dependence of Ce $M_{4,5}$ spectra and the charge distribution of the Ce $4f$ states. The experimental resolution can be orders of magnitude larger than the $4f$ crystal field splitting itself. To demonstrate the experimental feasibility of the method, we investigated CePd$_2$Si$_2$, thereby settling an existing disagreement about its crystal-field ground state.

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P. Hansmann, A. Severing, Z. Hu, M. W. Haverkort, C. F. Chang, S. Klein, A. Tanaka, H. H. Hsieh, H. -J. Lin, C. T. Chen, B. Fåk, P. Lejay, L. H. Tjeng. 2007-10-15. Determining the crystal-field ground state in rare earth Heavy Fermion materials using soft-x-ray absorption spectroscopy. https://doi.org/10.1103/physrevlett.100.066405

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