SCALING APPROACH TO THE INPLANE RESISTIVITY OF SINGLE-CRYSTALLINE LA1.85SR0.15CUO4 AS A FUNCTION OF TEMPERATURE, MAGNETIC-FIELD AND ITS ORIENTATION

Scaling approach to the in-plane resistivity in the mixed state of La1 .85Sr0.15SrCuO4 as a function of temperature (T), magnetic field (H), and angle(theta) between the field and the ab-planes is examined in te rms of different models. It is firstly shown that the /sin theta/ scal ing by the two-dimensional (2-D) vortex pancake model is inappropriate to the present system. Although scaling approach to the data could be formally performed according to the quasi-2-D model proposed by Tinkh am, the anisotropy extracted from the scaling is decreased with temper ature, which is contrary to the quasi-2-D prediction. Best scaling is obtained with the anisotropic three-dimensional (3-D) model. The tempe rature-independent anisotropy parameter (gamma similar to 14.7) so obt ained is consistent with the anisotropic 3-D model for strongly couple d superconducting layers.