POSSIBLE EVIDENCE OF CHARGE-STRIPE ORDERING IN THE ab-PLANE RESISTIVITY OF STRONGLY UNDERDOPED La2-xSrxCuO4 SINGLE CRYSTALS

Abstract

We measured the ab-plane resistivity of La 2-x Sr x CuO 4 underdoped single crystals (x = 0.052 and x=0.06) between 4.2 and 300 K by using an AC version of the Van der Pauw technique. We suggest that a possible scenario of charge-stripe ordering at the lowering of the temperature can be delineated by starting from the main features of the ρ ab (T) curves of these samples. In particular, the deviation from the linearity of the ab-plane resistivity, occurring at a temperature T ch , could be related to the beginning of the charge localization, and the upturn of ρ ab to the progressive pinning of the resulting charge stripes. By starting from an analysis of our ab-plane resistivity curves, we determined the temperature of charge ordering T ch for our samples, thus extending in consistent way the T ch vs. x curve reported in literature to the very low-doping region of the phase diagram.