‘Giant’ normal state magnetoresistances of Bi<InlineEquation ID="Equ1"> <EquationSource Format="TEX">$\mathsf{_{2}}$</EquationSource> </InlineEquation>Sr<InlineEquation ID="Equ2"> <EquationSource Format="TEX">$\mathsf{_{2}}$</EquationSource> </InlineEquation>CaCu<InlineEquation ID="Equ3"> <EquationSource Format="TEX">$\mathsf{_{2}}$</EquationSource> </InlineEquation>O <InlineEquation ID="Equ4"> ...

Magnetoresistance (MR) of Bi-2212 single crystals with <InlineEquation ID="Equ5"> <EquationSource Format="TEX">$T_{c} \approx 87-92$</EquationSource> </InlineEquation> K is studied in pulsed magnetic fields up to 50 T along the c-axis in a wide temperature range. The negative out-of-plane and the positive in-plane MRs are measured in the normal state. Both MRs have similar magnitudes, exceeding any orbital contribution by two orders in magnitude. These are explained as a result of the magnetic pair-breaking of preformed pairs. Resistive upper critical fields H <Subscript> c2</Subscript>(T) determined from the in- and out-of-plane MRs are about the same. They show non-BCS temperature dependences compatible with the Bose-Einstein condensation field of preformed charged bosons. Copyright Springer-Verlag Berlin/Heidelberg 2004