Structure of the superconducting high-pressure phase of Sc3CoC4

We investigate pressure-induced structural changes to the Peierls-type distorted low-temperature phase of the low-dimensional Sc3₃Co⁢C₄ as a possible origin of its pressure-enhanced superconductivity. By means of cryogenic high-pressure x-ray diffraction experiments we could reveal subtle, but significant structural differences between the low-temperature phase at ambient and elevated pressures. We could thus establish the structure of the superconducting phase of the title compound, which interestingly still shows the main features of the Peierls-type distorted low-temperature phase. This indicates that in contrast to other low-dimensional materials a suppression of periodic structural distortions is no prerequisite for superconductivity in the transition-metal carbide.