Abstract (EN):
We report results of thermoelectric power measurements (S(T)) in ferrimagnetic Gd-4(Co1-xCux)(3) compounds with x = 0.05, 0.1, 0.2, and 0.3, in the temperature range 8-300 K. Whereas in Gd4Co3, S(T) is always negative, for x > 0 the substitution of Co for Cu gives rise to the appearance of a low temperature positive maximum in S(T) at around 30 K. Based on our previous study of these compounds, we argue that this maximum in S(T) originates from electron-magnon scattering and is sensitive to electron band structure changes resulting from the substitution of Co for Cu 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, 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 a low temperature maximum in S(T) for x > 0. (C) 2011 American Institute of Physics. [doi:10.1063/1.3549597]
Language:
English
Type (Professor's evaluation):
Scientific
No. of pages:
2