Electron spin resonance of Gd3+ in the antiferromagnetic heavy fermion CeIn3 and its reference compound LaIn3
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Data
2009-10-15
Autores
Bittar, E. M.
Duque, J. G. S.
Venegas, Pablo Antonio [UNESP]
Rettori, C.
Pagliuso, P. G.
Título da Revista
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Editor
Elsevier B.V.
Resumo
We report temperature dependent electron spin resonance (ESR) experiments of Gd3+ in CeIn3 and in its reference compound LaIn3 taken in crushed single crystals. For LaIn3 a single Dysonian Gd3+ ESR line with a nearly temperature independent g similar to 2.020(5) is observed, and its linewidth follows a Korringa-like behavior as a function of temperature. From the Korringa rate (Delta H/Delta T similar to 16 Oe/K) and g-shift (Delta g similar to 0.027) we have extracted the exchange parameter between the Gd3+ local moments and the conduction electrons (ce) in this compound. This exchange parameter J(fs) approximate to 20 meV was found to be ce wave-vector independent. For CeIn3, the Gd3+ ESR spectra were found to be weakly temperature dependent and present partly resolved Gd3+ fine-structure. Interestingly, for CeIn3, the g-shift with respect to the g-value of Gd3+ in insulators is negative, in contrast to the positive g-shift found for Gd3+ in LaIn3. These results suggests different electronic structure at the Gd3+ site in the Kondo antiferromagnet host CeIn3. Possibly, Kondo effect may cause a decrease of the s-like conduction electron density of states at the Gd3+ site, giving arise to an exchange interaction only between the Gd3+ local moment and the Ce 4f electrons. (C) 2009 Elsevier B.V. All rights reserved.
Descrição
Palavras-chave
Heavy fermions, CeIn3, Electron spin resonance (ESR), Electronic structure
Como citar
Physica B-condensed Matter. Amsterdam: Elsevier B.V., v. 404, n. 19, p. 2995-2998, 2009.