A. V. Tkach

Quasi-two-dimensional transport properties of the layered superconductor Nd2−xCe x CuO4+δ

AbstractThe temperature dependences of resistivities ρab in the ab plane and ρc along the c axis have been studied for single-crystal Nd2 − xCexCuO4 + δ (x = 0.12, 0.15, 0.17, 0.20) films with (001) and (1

Recovery of deformation potential from the experimental information

\bar 1

Reconstruction of the deformation potential at the N-ellipsoid of the fermi surface of tungsten

0) orientations. The superconducting transition temperature and anisotropy coefficient are shown to be maximal in optimally annealed samples (the oxygen content is close to the stoichiometric content, δ → 0). A combination of the metallic behavior of the ρab(T) dependence and the nonmetallic behavior of the ρc(T) dependence for the optimally annealed samples is an intrinsic property of the substance and an indication of the fact that the system is quasi-two-dimensional. This layered quasi-two-dimensional system is an Anderson dielectric with a strongly anisotropic localization radius (Rlocab ≫ Rlocc). An increase in the oxygen content and, hence, in the degree of disorder in the Nd2 − xCexCuO4 + δ system is found to decrease the resistivity anisotropy coefficient. Thus, a disorder-induced Anderson transition takes place in this quasi-two-dimensional system.

Geometric oscillations: relaxational switching of modes

Resistive and magnetic measurements are made on La1.85−4∕3xSr0.15+4∕3xCu1−xMnxO4 ceramics with x=0.02, 0.04, 0.06, and 0.08. It is found that at these concentrations the temperature of the beginning and end of the superconducting transition depend weakly on the concentration x. The resistive properties exhibit a combination of metallic conductivity (or superconductivity) along the grains with hopping transport between grains. At low temperatures the superconductivity apparently coexists with two different magnetic phases.

Low temperature phase transition in ZnSe doped with nickel

Abstract We report a corrected formula, which connects deformation-dependent variations of the quantum oscillation frequency with a deformation potential component averaged over the effective orbit. Opportunities for mapping local values of deformation potential at the Fermi surface are also discussed.

Lattice instability in ZnSe:Ni crystal

AbstractTemperature dependences of resistivity ρab(T) and ρc(T) of single-crystal films Nd2 − xCexCuO4 + δ (x = 0.12, 0.15, 0.17, 0.20) with orientations (001) and

Quasi-two-dimensional transport properties of the layered superconductor Nd 2 - x

(1\overline 1 0)