Busca avançada
Ano de início
Entree
(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.)

Superconductivity in monocrystalline YNiSi3 and LuNiSi3

Texto completo
Autor(es):
Arantes, Fabiana R. [1] ; Aristizabal-Giraldo, Deisy [1, 2] ; Mayoh, Daniel A. [3] ; Yamane, Yu [4] ; Yang, Chongli [4] ; Lees, Martin R. [3] ; Osorio-Guillen, Jorge M. [2] ; Takabatake, Toshiro [4] ; Avila, Marcos A. [1]
Número total de Autores: 9
Afiliação do(s) autor(es):
[1] Univ Fed ABC UFABC, CCNH, Santo Andre, SP - Brazil
[2] Univ Antioquia UdeA, Inst Fis, Calle 70 52-21, Medellin - Colombia
[3] Univ Warwick, Dept Phys, Coventry CV4 7AL, W Midlands - England
[4] Hiroshima Univ, Grad Sch Adv Sci Matter, Higashihiroshima 7398530 - Japan
Número total de Afiliações: 4
Tipo de documento: Artigo Científico
Fonte: Physical Review B; v. 99, n. 22 JUN 11 2019.
Citações Web of Science: 0
Resumo

We report the discovery of bulk superconductivity in the ternary intermetallics YNiSi3 and LuNiSi3. High-quality single crystals were grown via the Sn-flux method and studied using magnetization, specific-heat, and resistivity measurements at low temperatures. The critical temperatures obtained from these different techniques are in very good agreement and yield T-c = 1.36(3) K and T-c = 1.61(2) K for YNiSi3 and LuNiSi3, respectively. Magnetization measurements indicate that both compounds are among the rare cases where type-I superconductivity occurs in a ternary intermetallic, however, the jump in the specific heat at the transition is lower than the value expected from BCS theory (Delta C-el/gamma T-n(c) = 1.43) in both materials and is equal to 1.14(9) and 0.71(5) for the Y and Lu compounds, respectively. Resistivity measurements exhibit sharp transitions but with critical fields mu H-0(c)(0) (approximate to 0.05 T for YNiSi3 and approximate to 0.08 T for LuNiSi3) considerably higher than those obtained from the magnetization and specific heat (approximate to 0.01 T). First-principles density functional theory calculated electronic structure shows that these compounds have highly anisotropic and complex Fermi surfaces with one electronic and two holelike branches. One hole branch and the electron branch have a large cylindrical topology connecting the first Brillouin-zone boundaries, the former being built up by the hybridization of Y(Lu) d, Ni d, and Si p states, and the latter being built up by Ni d and Si p states. The calculated phononic structures indicate that the coupling of the Y(Lu), Ni d, and Si p electrons in the low-lying optical phonon branches is responsible for the formation of Cooper pairs and the observed superconducting state. Therefore, these compounds can be classified as anisotropic three-dimensional metals with multiband superconducting ground states in the weak-coupling regime. (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: 14/20365-6 - Preparação e caracterização de novos clatratos termoelétricos contendo terras raras trivalentes e aceitadores mistos
Beneficiário:Fabiana Rodrigues Arantes
Linha de fomento: 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
Linha de fomento: Auxílio à Pesquisa - Temático
Processo FAPESP: 17/01827-7 - Caracterização termoelétrica de monocristais de clatratos tipo-I Ba8GayMzGe46-y-z (M = Au, Ag, Cu) e Ba8-xRxGayAgzGe46-y-z (R = La, Ce, Eu)
Beneficiário:Fabiana Rodrigues Arantes
Linha de fomento: Bolsas no Exterior - Estágio de Pesquisa - Pós-Doutorado