Staging superstructures in high-T_c Sr/O codoped La_2-xSr_xCuO_4+y

TY - JOUR

T1 - Staging superstructures in high-Tc Sr/O codoped La2-xSrxCuO4+y

AU - Ray, P. J.

AU - Andersen, Niels Hessel

AU - Jensen, T.B.S.

AU - Mohottala, H. E.

AU - Niedermayer, Ch.

AU - Lefmann, Kim

AU - v.Zimmermann, M.

AU - Udby, Linda

PY - 2017/11/9

Y1 - 2017/11/9

N2 - We present high-energy x-ray diffraction studies on the structural phases of an optimal high-Tc superconductor La2−xSrxCuO4+y tailored by co-hole-doping. This is specifically done by varying the content of two very different chemical species, Sr and O, respectively, in order to study the influence of each. A superstructure known as staging is observed in all samples, with the staging number n increasing for higher Sr dopings x. We find that the staging phases emerge abruptly with temperature, and can be described as a second-order phase transition with transition temperatures slightly depending on the Sr doping. The Sr appears to correlate the interstitial oxygen in a way that stabilizes the reproducibility of the staging phase both in terms of staging period and volume fraction in a specific sample. The structural details as investigated in this paper appear to have no direct bearing on the electronic phase separation previously observed in the same samples. This provides evidence that the electronic phase separation is determined by the overall hole concentration rather than specific Sr/O content and concomitant structural details.

AB - We present high-energy x-ray diffraction studies on the structural phases of an optimal high-Tc superconductor La2−xSrxCuO4+y tailored by co-hole-doping. This is specifically done by varying the content of two very different chemical species, Sr and O, respectively, in order to study the influence of each. A superstructure known as staging is observed in all samples, with the staging number n increasing for higher Sr dopings x. We find that the staging phases emerge abruptly with temperature, and can be described as a second-order phase transition with transition temperatures slightly depending on the Sr doping. The Sr appears to correlate the interstitial oxygen in a way that stabilizes the reproducibility of the staging phase both in terms of staging period and volume fraction in a specific sample. The structural details as investigated in this paper appear to have no direct bearing on the electronic phase separation previously observed in the same samples. This provides evidence that the electronic phase separation is determined by the overall hole concentration rather than specific Sr/O content and concomitant structural details.

U2 - 10.1103/physrevb.96.174106

DO - 10.1103/physrevb.96.174106

M3 - Journal article

SN - 2469-9950

VL - 96

JO - Physical Review B

JF - Physical Review B

M1 - 174106

ER -