Magnetoresistance and Hall effect in electron-doped superconductor [Nd.sub.2-x][Ce.sub.x]CU[O.sub.4 + δ] with different degrees of nonstoichiometric disorder: a two-band mode

Investigations have been performed on the magnetic-field dependences of the longitudinal and Hall resistivity of the electron-doped [Nd.sub.2-x][Ce.sub.x]Cu[O.sub.4 + δ] system with an optimum content of cerium (x = 0.15) and different degree of the nonstoichiometric disorder in magnetic fields of up to 8 T(B∥c; J∥ ab) in a temperature range of 0.4-4.2 K. The observed anomalous dependences of the Hall coefficient R(B) along with the dependences of the electrical resistivity ρ(B) have been interpreted based on the Drude-Lorentz model in the case of the normal state and in the Bardeen-Stephen model in the mixed state modified with allowance for the coexistence of two types of charge carriers with the opposite charge signs (electrons and holes). Keywords: galvanomagnetic effects, nonstoichiometric disorder, electron-doped cuprate superconductors DOI: 10.1134/S0031918X14050032