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(Referência obtida automaticamente do Web of Science, por meio da informação sobre o financiamento pela FAPESP e o número do processo correspondente, incluída na publicação pelos autores.)

Tuning the electronic hybridization in the heavy fermion cage compound YbFe2Zn20 with Cd doping

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Cabrera-Baez, M. ; Ribeiro, R. A. ; Avila, M. A.
Número total de Autores: 3
Tipo de documento: Artigo Científico
Citações Web of Science: 3

The tuning of the electronic properties of heavy fermion compounds by chemical substitution provides excellent opportunities for further understanding the physics of hybridized ions in crystal lattices. Here we present an investigation on the effects of Cd doping in flux-grown single crystals of the complex intermetallic cage compound YbFe2Zn20, which has been described as a heavy fermion with a Sommerfeld coefficient of 535 mJ mol(-1) . K-2. The substitution of Cd for Zn disturbs the system by expanding the unit cell and, in this case, the size of the Zn cages that surround the Yb and Fe. With an increasing amount of Cd, the hybridization between the Yb 4f electrons and the conduction electrons is weakened, as shown by a decrease in the Sommerfeld coefficient, which should be accompanied by a valence shift of the Yb3+ due to the negative chemical pressure effect. This scenario is also supported by the low temperature DC magnetic susceptibility, which is gradually suppressed and shows an increment of the Kondo temperature, based on a shift to higher temperatures of the characteristic broad susceptibility peak. Furthermore, the DC resistivity decreases with the isoelectronic substitution of Cd for Zn, contrary to expectations in an increasingly disordered system, and implying that the valence shift is not related to charge carrier doping. The combined results demonstrate the excellent complementarity between positive physical pressure and negative chemical pressure, and point to a rich playground for exploring the physics and chemistry of strongly correlated electron systems in the general family of Zn-20 compounds, despite their structural complexity. (AU)

Processo FAPESP: 12/17562-9 - Preparação de monocristais orientados para estudos de anisotropias eletrônicas, magnéticas e térmicas
Beneficiário:Marcos de Abreu Avila
Linha de fomento: Auxílio à Pesquisa - Regular
Processo FAPESP: 11/19924-2 - Estudo e desenvolvimento de novos materiais avançados: eletrônicos, magnéticos e nanoestruturados: uma abordagem interdisciplinar
Beneficiário:Carlos Rettori
Linha de fomento: Auxílio à Pesquisa - Temático