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

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.

arXiv comment14 pages, 4 figures

References in corpus (12)

• Superconductivity Near Ferromagnetism in MgCNi3
• Electronic structures of antiperovskite superconductors: MgXNi${}_3$ (X=B,C,N)
• Superconductivity and Electronic Structure of Perovskite MgCNi3
• Electronic structure, magnetism and superconductivity of MgCNi${}_3$
• Carbon Concentration Dependence of the Superconducting Transition Temperature and Structure of MgCxNi3
• Strong magnetic pair breaking in Mn substituted MgB_2 single crystals
• The suppression of superconductivity in MgCNi3 by Ni-site doping
• Influence of Carbon Concentration on the Superconductivity in MgCxNi3
• Thermopower and thermal conductivity of superconducting perovskite $MgCN{i}_3$
• The suppression of superconductivity in Mn substituted MgCNi${}_3$
• The Effect of Ru substitution for Ni on the superconductivity in MgCNi3-xRux
• The effect of {11}^B substitution on the superconductivity in MgCNi3

Cited by in corpus (1)

• Superconducting energy gap in MgCNi3 single crystals: Point-contact spectroscopy and specific-heat measurements