Intralayer carbon substitution in the MgB 2 superconductor

By T. Takenobu, T. Ito, D. H. Chi, K. Prassides, Yoshihiro Iwasa. 2001

162 citations recorded by the source corpus.

We report that the ternary ${\mathrm{MgB}}_{2\ensuremath{-}x}{\mathrm{C}}_{x}$ compounds adopt an isostructural ${\mathrm{AlB}}_{2}$-type hexagonal structure in a relatively small range of nominal carbon concentration, $xl0.1.$ The lattice parameter a decreases almost linearly with increasing carbon content x, while the c parameter remains unchanged, indicating that carbon is exclusively substituted in the boron honeycomb layer without affecting the interlayer interactions. The superconducting transition temperature ${T}_{c}$ decreases quasilinearly as a function of the carbon concentration, with a slope steeper than that for the isoelectronic ${\mathrm{Mg}}_{1\ensuremath{-}x}{\mathrm{Al}}_{x}{\mathrm{B}}_{2}.$

Subfields: Condensed Matter Physics, Electronic, Optical and Magnetic Materials, Materials Chemistry

View Paper: https://www.semanticscholar.org/paper/dad7d732c0ab9dce67b63db3f6e36386ffb70471