^{195Pt and ¹¹B NMR studies of LaPt₂B₂C and YNi₂B₂C}

Kumagai, K., Ikeda, S., Roos, J., Mali, M., Brinkmann, D.

Physica C (Netherlands), vol.272, no.3-4, 301-8, 1 Dec. 1996

Abstruct
^{195Pt and ¹¹B have been investigated by NMR in the normalstate of the quaternary superconductors, LaPt₂B₂C (Tc=12 K) and YNi₂B₂C (Tc=16 K) between 4 and 400 K. The ¹¹B Knight shift and 1/T₁T increase with decreasing temperature in YNi₂B₂C. In contrast, T₁T and the Knight shift of ¹⁹⁵Pt in LaPt₂B₂C are almost temperature independent. The value of 1/T₁T of ¹⁹⁵Pt in LaPt₂B₂C is 6 times smaller than that of metal Pt, indicating that the density of states of 5d conduction electrons at the Pt site is small and that there is no evidence of dominant antiferromagnetic correlations. The NMR results are considered to be consistent with band structure calculations, and suggest a conventional superconductivity mediated by electron-phonon interactions in the quaternary borocarbides.}