The 2D weak localization effects at low temperatures T = (0.2 ÷ 4.2) K have been investigated in nonsuperconducting sample Nd1.88Ce0.12CuO 4−δ and in the normal state of the superconducting sample Nd1.82Ce0.18CuO 4−δ for B > Bc2 ≃ 3 T . The phase coherence time τϕ(≃ 5 · 10 −11 s at 1.9 K) and the effective thickness of a conducting CuO2 layer d(≃ 1.5Å) have been estimated by the fitting of 2D weak localization theory expressions to the magnetoresistivity data for the normal to plane and the in-plane magnetic fields. The estimation of the parameter d ensures the condition of a strong carrier confinement and makes a basis to the model of almost decoupled 2D metallic sheets for the Nd2−xCexCuO 4−δ single crystals.
The influence of nonstoichiometric disorder on the in-plane resistivity and SCtransition has been investigated for Nd 2−x Ce x CuO 4+δ single crystal films (x = 0.15 and 0.18). It is shown that with increasing of δ the in-plane normal state resistivity increases (the mean free path diminishes) and SC-transition temperature decreases with essential broadening of the transition region. The observed evolution from homogeneous metallic (and superconducting) Nd 2−x Ce x CuO 4+δ system to inhomogeneous dielectric one is described as Anderson-type disorder-induced transition in a two-dimensional electron system.
The results of a study of the temperature dependences of the resistivity and its anisotropy coefficient in the normal phase of single-crystal Nd2−xCexCuO4+δ films with different degrees of cerium doping x and oxygen content δ are presented. Two types of films of identical composition are considered, grown with the orientation of the c axis of the crystal perpendicular to and parallel to the plane of the substrate. The parameters found from an analysis of the conductivity and Hall coefficient are presented for the 18 samples studied.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.