Superconductivity and charge density wave formation in TlxV6S8

• Published in: New journal of physics Vol. 15; no. 8; pp. 083008 - 83022
• Main Authors: Miclea, C F, Hochheimer, H D, Martin, B, Miclea, C, Ohtani, T
• Format: Journal Article
• Language: English
• Published: IOP Publishing 02-08-2013
• ISSN: 1367-2630
• DOI: 10.1088/1367-2630/15/8/083008

We report on specific heat and resistivity measurements under hydrostatic pressure on the quasi-one dimensional metal TlxV6S8. We studied the interplay between the low temperature superconducting (SC) ground state and a high temperature charge density wave (CDW) instability. We observed a clear dependency of the physical properties of TlxV6S8 on the Tl concentration x. The CDW anomaly is present in all investigated samples that are strongly enhanced at half Tl filling, x = 0.47. This is also the only composition for which no signature of superconductivity is observed. The specific heat results regarding the SC phase in Tl0.63V6S8 suggest that this compound is a highly anisotropic, weak coupling superconductor. Pressure suppresses both SC and CDW transitions to lower temperatures. Nevertheless, as the CDW gap is closed at a critical pressure pc, the increase in the density of states leads to a small enhancement of Tc suggesting that SC and CDW compete for parts of the Fermi-surface.