2D Superconductivity in LSCO Single Crystals

TYPECondensed Matter Seminar
Organizer:M. Reznikov
Location:Lidow Nathan Rosen (300)

We report direction dependent magnetization measurements in La2-xSrxCuO4 single crystals. The crystals were grown using traveling solvent floating zone method and where cut into rectangular needle-like shapes with the "c" direction parallel or perpendicular to the needle symmetry axis. The magnetic anisotropies were studied in details near the critical temperatures using a SQUID magnetometer. The measurements were done in the zero field limit using magnetic field H < 1 Oe, which is lower than the critical field Hc1 at T->Tc. A difference in Tc of 0.65 K was observed between parallel and perpendicular direction of the optimally doped samples (x=0.15). Higher anisotropy of 2.9 K was observed in under doped sample (x=0.08). We confirmed that the effect is not caused by sample inhomogeneity, needle dimensions, cooling rates, misalignment est.. Our results indicate that there is a temperature region where La2-xSrxCuO4 is a two dimensional superconductor from the Meissner effect point of view.