Observation of a Charge Density Wave Incommensuration Near the   Superconducting Dome in CuxTiSe2
  X-ray diffraction was employed to study the evolution of the charge density wave (CDW) in CuxTiSe2 as a function of copper intercalation in order to clarify the relationship between the CDW and superconductivity. The results show a CDW incommensuration arising at an intercalation value coincident with the onset of superconductivity at around x=0.055(5). Additionally, it was found that the charge density wave persists to higher intercalant concentrations than previously assumed, demonstrating that the CDW does not terminate inside the superconducting dome. A charge density wave peak was observed in samples up to x=0.091(6), the highest copper concentration examined in this study. The phase diagram established in this work suggests that charge density wave incommensuration may play a role in the formation of the superconducting state. 
Anshul Kogar, Gilberto A. de la Pena, Sangjun Lee, Yizhi Fang, Stella   X.-L. Sun, David B. Lioi, Goran Karapetrov, Kenneth ...
cond-mat.supr-con cond-mat.str-el