Microscopic Charge Inhomogeneities in Underdoped La2−xSrxCuO4: Local Structural Evidence

We present local structural evidence for the existence of charge inhomogeneities at low temperature in underdoped and optimally doped La2−xSrxCuO4. The inhomogeneities disappear for x ≥ 0.2. The evidence for the charge inhomogeneities comes from an anomalous increase in the inplane Cu–O bond length distribution in the underdoped samples as well as evidence for CuO6 octahedral tilt inhomogeneities in the intermediate range structure. Preliminary analysis of the temperature dependence of this phenomenon indicates that the inhomogeneities set in at temperatures in the range 60 K < Tco < 130 K, which depends on doping.