Fizika Nizkikh Temperatur: Volume 45, Number 2 (February 2019), p. 245-250 ( to contents , go back )
Anisotropy of the critical current density in the layered electron-doped superconductor Nd2–xCexCuO4+δ
A.S. Klepikova1, M.R. Popov1, A.A. Ivanov2, M.V. Medvedev3, and T.B. Charikova1,4
1Institute of Metal Physics RAS, Ekaterinburg 620041, Russia
2National Research Nuclear University MEPhI (Moscow Engineering Physics Institute) 31 Kashirskoe Shosse, Moscow 115409, Russia
3Institute for Electrophysics, Russian Academy of Sciences, Ural Branch 106 Amundsen Str., Ekaterinburg 620016, Russia
4Ural Federal University, Yekaterinburg 620002, Russia
Received October 3, 2018, published online December 20, 2018
The results of studies of the conductivity and critical current density of single-crystal films Nd2–xCexCuO4+δ/SrTiO3 with an axis c perpendicular or parallel to the substrate plane with a cerium concentration of x = 0.15 and x = 0.17 are presented. It was found that in the stoichiometrically annealed films with the optimum cerium content (x = 0.15) the resistance anisotropy is maximal and the anisotropy of the critical current density is jcab/jcc≅3•103 at Т = 4.2 К. The strong anisotropy of the critical current density is considered within the framework of the natural superlattices with alternating conducting CuO2 layers and nonconducting Nd(Ce)O-buffer layers. It was found that the high density of the critical current along the conducting CuO2 planes is related to the pinning of vortices on the buffer layers and a strong anisotropy of the critical current density is a manifestation of the anisotropic motion of the vortex lattice in a layered superconductor.
Key words: electron-doped superconductor, critical current density, anisotropy of transport properties.