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arXiv · 0706.2180

The effect of Fe and Ru substitution for Ni on the thermopower in MgCNi_3

C. Sulkowski·T. Klimczuk·R. J. Cava·K. Rogacki
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Abstract

The intermetallic perovskite MgCNi3 is a superconductor with a Tc=7 K. Substitution of Fe and Ru for Ni decreases Tc monotonically as the doping concentration is increased. Here we report thermopower measurements, S(T), on MgCNi3, MgCNi3-xFex and MgCNi3-xRux. For MgCNi3, the thermopower is negative, - 12.5 mikroV/K, at 300 K. The absolute value of S decreases as x increases in MgCNi3-xFex and MgCNi3-xRux. The sign of S changes from negative to positive at low temperatures for values of x > 0.01. These data show that the carriers in MgCNi3 are electrons, and by increasing x and decreasing temperature, the participation of hole carriers clearly increases. The influence of the magnetic moments of the Fe atoms on the thermopower is not visible.

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C. Sulkowski, T. Klimczuk, R. J. Cava, K. Rogacki. 2007-06-14. The effect of Fe and Ru substitution for Ni on the thermopower in MgCNi_3. https://doi.org/10.1103/physrevb.76.060501

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