Thermoelectric Power of Gd4(Co-A)3 Compounds (A = Cu, Pt)

• Tipo: Artigo em Revista Científica Internacional
• Data: 2012

Autores

Teresa Seixas (Autor) FCUP; M. A. Salgueiro da Silva (Autor) FCUP; Braun, HF (Autor) Outra; Eska, G (Autor) Outra

Revista

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Título: Materials Science Forum - MSF

Vol. 730-732

Páginas: 159-163

ISSN: 1662-9752

Indexação

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Outras Informações

ID Authenticus: P-00J-5RR

DOI: 10.4028/www.scientific.net/msf.730-732.159

Abstract (EN): We report on a comparative study of thermoelectric power measurements (S(7)) in ferrimagnetic Gd-4(Co(1-x)A(x))(3) compounds with A = Cu, Pt, in the temperature range 8 K - 300 K. Whereas in Gd4Co3 S(T) is always negative, for x > 0 the substitution of Co for Cu/Pt gives rise to the appearance of a low temperature positive maximum in S(2) at around 30 K. Based on our previous study of Gd-4(Co1-xCux)(3) compounds, we argue that this maximum in S(7) originates from electron-magnon scattering and is sensitive to electron band structure changes resulting from the substitution of Co for Cu/Pt and the accompanying reduction in the ratio between the electron-magnon and the electron-phonon scattering strengths. The decreasing role of Co 3d electrons with the progressive substitution of Co for Cu/Pt, evidenced by a strong reduction in the spin disorder resistivity and the Co magnetic moment, is seen to be crucial for the existence of such low temperature maximum in S(T) for x > 0. It is seen that the substitution of Co for Pt leads to higher values of the amplitude and temperature of the positive maximum in S(T) than the substitution of Co for Cu.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 5