POSSIBLE FLUCTUATION ORIGIN OF THE ANOMALIES IN THE C-AXIS MAGNETORESISTANCE OBSERVED IN BI2SR2CACU2O8-TEMPERATURE(X ABOVE THE CRITICAL)

An expression for the transverse magnetoresistance above T-c has been derived from the theory of fluctuation contribution to the c-axis cond uctivity of layered superconductors under an external magnetic field,, which was recently developed by Dorin et al. The suppression of fluct uations due to the magnetic field leads to a decrease of the negative fluctuation contribution to the conductance, and therefore to a negati ve transverse magnetoresistance at temperatures not too close to T-c. The formula derived from the theory has been compared with the availab le experimental data of the magnetoresistance of BSCCO single crystals obtained by Ong et al. at temperatures 10-20 K above T-c. The quadrat ic increase of the relative magnetoresistance with the field and its t emperature dependence are explained clearly. A quantitative fit to the experimental data shows a remarkable agreement of the theory with exp eriment, and allows to extract the values of several physical paramete rs. (C) 1995 American Institute of Physics.