Magnetoresistance and high-temperature resistivity of Bi_2.1Sr_1.9Ca_1.0Cu₂O _8+δ single crystals

We have measured the normal state magnetoresistance (-Δσ_⊥; B ⊥ I ⊥ c, - Δσ_∥; B∥I ⊥ c) of a Bi_2.1Sr_1.9Ca_1.0Cu₂O _8+δ single crystal. At low temperatures (ε≡(T - T_c)/T_c ≤, 0.1), the orbital magnetoresistance (-Δσ_⊥ + Δδ_∥) can be well fitted by the 2D limit of the Aslamazov-Larkin (AL) fluctuation (-Δ_ALO α ε^-3). At high temperatures (ε > 0.1), it can be fitted either by the contribution of the Maki-Thompson (MT) fluctuation or by the anomalous normal state magnetoresistance. We have also measured the resistivities of these crystals up to 870 K and found that in this slightly overdoped region the scattering rate can be expressed as a sum of the typical T-linear and the T² components. The T² component can be assigned to electron-electron scattering originating from the Fermi liquid.