DETERMINATION OF THE LOCAL LATTICE DISTORTIONS IN THE CUO2 PLANE OF LA1.85SR0.15CUO4

The measurement of the Cu-O distances by a local and fast probe, polarized Cu {ital K}-edge extended x-ray absorption fine structure (EXAFS) in La{sub 1.85}Sr{sub 0.15}CuO{sub 4} crystal shows two different conformations of the CuO{sub 6} octahedra below 100 K assigned to two types of stripes with different lattice. This experiment supports a model of {open_quote}{open_quote}two components{close_quote}{close_quote} spatially separated in a superlattice of quantum stripes for the anomalous properties of cuprate superconductors. {copyright} {ital 1996 The American Physical Society.}