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

• Type: Article in International Scientific Journal
• Date: 2012

Authors

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

Journal

Title: Materials Science Forum

Vol. 730-732

Pages: 159-163

ISSN: 0255-5476

Publisher: Trans Tech Publications Ltd

Indexing

ISI Web of Knowledge - 0 Citations

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Other information

Authenticus ID: 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.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 5