Normal state magnetoresistance in Bi2Sr2CaCu2O8+delta thin films with different oxygen contents

We report preliminary results obtained in a magneto-transport study in the normal state of overdoped (T-c similar to 63 K) and underdoped(T-c similar to 60 K and T-c similar to 30 K) Bi2Sr2CaCu2O8+delta thin films. In all cas es the transverse magnetoresistance (H\\c with in-plane current) is positiv e and proportional to H-2 UP to 20 T for temperatures above approximately 1 10 K and does not follow Kohler's rule. No proportionality between the magn etoresistance and the square of the Hall angle theta(H) is observed, as wou ld be expected if both quantities were governed by the same relaxation time tau(H) In the high-temperature range the magnetoresistance of the underdop ed samples appears to saturate in the vicinity of the temperature T* where the resistivity shows a downturn from T-linear dependence. (C) 1999 Elsevie r Science B.V. All rights reserved.