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arXiv · 0801.1191

Relevance of ferromagnetic correlations for the Electron Spin Resonance in Kondo lattice systems

Cornelius Krellner·Tobias Foerster·Hirale Jeevan·Christoph Geibel·Joerg Sichelschmidt
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Abstract

Electron Spin Resonance (ESR) measurements of the ferromagnetic Kondo lattice system CeRuPO show a well defined ESR signal which is related to the magnetic properties of the Ce3+ moment. In contrast, no ESR signal could be observed in the antiferromagnetic homologue CeOsPO. Additionally, we detect an ESR signal in a further ferromagnetic Yb compound, YbRh, while it was absent in a number of Ce or Yb intermetallic compounds with dominant antiferromagnetic exchange, independently of the presence of a strong Kondo interaction or the proximity to a (quantum) critical point. Thus, the observation of an ESR signal in a Kondo lattice is neither specific to Yb nor to the proximity of a quantum critical point, but seems to be connected to the presence of ferromagnetic fluctuations. These conclusions not only provide a basic concept to understand the ESR in Kondo lattice systems even well below the Kondo temperature as observed in the heavy fermion metal YbRh2Si2 but point out ESR as a prime method to investigate directly the spin dynamics of the Kondo ion.

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Cornelius Krellner, Tobias Foerster, Hirale Jeevan, Christoph Geibel, Joerg Sichelschmidt. 2008-01-08. Relevance of ferromagnetic correlations for the Electron Spin Resonance in Kondo lattice systems. https://doi.org/10.1103/physrevlett.100.066401

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