| Texto completo | |
| Autor(es): |
Cabrera-Baez, M.
;
Denis, V. C.
;
Mendonca-Ferreira, L.
;
Carlone, M.
;
Venegas, P. A.
;
Avila, M. A.
;
Rettori, C.
Número total de Autores: 7
|
| Tipo de documento: | Artigo Científico |
| Fonte: | PHYSICAL REVIEW B; v. 97, n. 22, p. 8-pg., 2018-06-22. |
| Resumo | |
We have studied the evolution of Y1-xGdxPb3 (0 <= x <= 1) from its superconducting (x = 0) to antiferromagnetic (x = 1) states with critical temperatures T-c = 4.6(2) K and T-N = 15.7(2) K, respectively. At relatively low Gd concentrations (x <= 0.03) Tc presents a weak but linear suppression with increasing x, as expected from the Abrikosov-Gorkov (AG) theory describing the Cooper pair breaking due to the exchange interaction between the impurity localized magnetic moment and the conduction electrons (ce). This linear T-c suppression rate leads to an effective exchange parameter of < J(2)(q)>(1/2)(AG) = 0.20(7) meV between the 4f localized electrons and the ce. For intermediate Gd concentrations (0.03 <= x <= 0.15), although no Gd clustering is observed, there is an unusual inflection and leveling off trend in T-c indicating that the superconducting phase persists until the highest Gd concentration in this region where magnetic interactions are evidenced by increasingly negative values of the Curie-Weiss temperature Theta(C). Analysis of low-T Gd3+ electron spin resonance (ESR) experiments and their ESR line-shape simulations, in conjunction with the trend in T-c, leads us to suggest that an exchange bottleneck mechanism between the Gd+3 localized magnetic moment and the ce may be the reason behind the inhibition of the Cooper pair-breaking mechanism, in favor of a magnetic interaction via ce polarization. Therefore, our superconducting and ESR results suggest a scenario where superconducting and magnetic phases coexist extensively in the Y1-xGdxPb3 system, mediated by different types of ce. (AU) | |
| Processo FAPESP: | 16/15780-0 - Estudo das propriedades físicas de materiais nanoestruturados e interações fundamentais em sistemas bulk |
| Beneficiário: | Michael Cabrera Baez |
| Modalidade de apoio: | Bolsas no Brasil - Pós-Doutorado |
| Processo FAPESP: | 11/19924-2 - Estudo e desenvolvimento de novos materiais avançados: eletrônicos, magnéticos e nanoestruturados: uma abordagem interdisciplinar |
| Beneficiário: | Carlos Rettori |
| Modalidade de apoio: | Auxílio à Pesquisa - Temático |