Carbon isotope effect in superconducting MgCNi_3
arXiv:cond-mat/0410504 · doi:10.1103/PhysRevB.70.212514
Abstract
The effect of Carbon isotope substitution on T_c in the intermetallic perovskite superconductor MgCNi_3 is reported. Four independent groups of samples were synthesized and characterized. The average T_c for the Carbon-12 samples was found to be 7.12(2) K and the average T_c for the Carbon-13 samples was found to be 6.82(2) K. The resulting carbon isotope effect coefficient is alfa_C = 0.54(3). This indicates that carbon-based phonons play a critical role in the presence of superconductivity in this compound.
To be published in Phys. Rev. B. 4 pages, 1 figure