Influence of magnetic field on the superconducting transition in a Nd1.82Ce0.18CuO4-δ film
Harus G.I., Ignatenkov A.N., Lerinman N.K., Ponomarev A.I., Sabirzyanova L.D., Shelushinina N.G., Babushkina N.A., Belova L.M.
The temperature and magnetic-field dependences of the resistivity ρ and Hall effect R (j||ab, B||c) in a Ndi .82Ceo.i 8óÉ04_{ single crystal film (Tc 6 K) is investigated at temperatures 1.4 < Τ < 20 ë and magnetic fields 0 < ÷ < 5.5 ô. At the lowest temperature Τ — 1.4 ë the resistive state (exhibiting resistivity and Hall effect) arises in a magnetic field B—0.5 T. A transition to the normal state is completed at Bc2 ~ 3 T, where the Hall coefficient becomes nearly constant. The negative magnetoresistance due to the weak-localization effect in the normal state is observed for ÷ > 3 ô. The nonmonotonic behavior and the inversion of the sign of R(B) in the mixed state are explained in a reasonable way by the flux-flow model with the effect of pinning taken into account. PACS: 74.60.Ec, 74.76.Bz