Experimental study of the resistivity tensor in Bi2Sr2CaCu2O8+x crystals by means of multi-terminal measurements

We present measurements of the in-plane (rho (ab)) and out-of-plane (rho (c )) resistivity in BSCCO single crystals. The resistivities are measured sim ultaneously on the same sample by means of a multi-terminal technique. Resu lts are presented in the normal state and in the superconducting state, bot h in presence and in absence of an applied magnetic field. We underline the main differences with standard four probe measurements, showing in which c ases the new method is strictly needed to avoid erroneous results. The tech nique is also able to test the locality of the dynamic: we present an accur ate experimental analysys of the temperature and magnetic field ranges wher e the dynamic is local or non local. We finally show that above T-c this me thod gives results reliable enough to allow for a detailed study of the exc ess conductivity. We find that the data do not follow simple Aslamazov-Lark in laws in temperature ranges wider than 1K, and that an accurate descripti on of the data over a wide temperature range must include the effects of a short-wavelength cutoff in the fluctuational spectrum.