Charge order and structural evolution in nematic superconductor Ba(0.33)Sr(0.67)Ni2As2

Recent discoveries of charge order in the cuprates and electron nematic order in the iron-based superconductors has pointed towards the possibilities of both orderings being tied to mechanisms of high Tc superconductivity. The (Ba,Sr)Ni2As2 superconducting system has very recently been shown to exhibit both types of ordering without the presence of any magnetic order. Through single crystal x-ray diffraction reports, the Ba parent compound shows the emergence of an incommensurate charge density wave (CDW) before transitioning from a tetragonal structure to a triclinic structure with the emergence of a new commensurate triclinic CDW. We report single crystal x-ray observations how the charge order and structure of the system has evolved up through a Sr concentration of x=.67, just before the complete extinction of the triclinic phase and maximal superconducting Tc.