Es. Bozin et al., Neutron diffraction evidence of microscopic charge inhomogeneities in the CuO2 plane of superconducting La2-xSrxCuO4 (0 <= x <= 0.30), PHYS REV L, 84(25), 2000, pp. 5856-5859
High-resolution atomic pair distribution functions have been obtained using
neutron powder diffraction data from La2-xSrxCuO4 over the range of doping
0 less than or equal to x less than or equal to 0.30 at 10 K. Despite the
average structure getting less orthorhombic, we see a broadening of thr in-
plane Cu-O bond distribution as a function of doping up to optimal doping.
Thereafter the peak abruptly sharpens. The peak broadening can be well expl
ained by a local microscopic coexistence of doped and undoped material. Thi
s suggests a crossover from a charge inhomogeneous state at and below optim
al doping to a homogeneous charge stale above optimal doping.