Electron-doped superconducting (La,Ce)₂CuO₄thin films grown by dc magnetron sputtering and their transport properties

Abstract

Electron-doped La 2−x Ce x CuO 4 (LCCO) thin films were successfully prepared on (100) SrTiO 3 substrates by the dc magnetron sputtering method. The optimal-doped films show a highly c-axis oriented single T -type structure, and the zero resistance temperature T C0 is 25 K. In the normal state, the nearly quadratic temperature dependence of the resistivity was found and attributed to the Landau-Fermi liquid behaviour due to electron-electron scattering. At the same time, the negative sign of the Hall coefficient for such films well above T C obviously confirms the electron-type nature. The optimal conditions for the growth of single-phase T -type LCCO thin films are also discussed in detail.

Low-temperature Hall effect in electron-doped superconductingLa2−xCexCuO4thin films

“…20,21 To obtain LCCO thin films with high quality, we carefully adjusted the deposition temperature, the ratio of Ar to O 2 , and the annealing process for each doping level. Owing to the undetermined oxygen content in films, we chose the highest T c and sharp transition of the annealed films for each Ce content.…”

Preparation of electron-doped La2−xCexCuO4±δ thin films with various Ce doping by dc magnetron sputtering

“…The targets were synthesized by conventional solid-state reaction [7]. To obtain the high quality LCCO thin films, we carefully adjusted the sputtering pressure, the deposition temperature, the gas ratio of Ar to O 2 , the deposition rate and the annealing process for each doping.…”

Metastable T′-phase in bulk La2−xLnxCuO4 (Ln=Sm and Y)

“…The film growth can be performed at rather lower temperature than bulk synthesis [6]. In recent years, the superconducting T 0 -La 2Àx Ce x CuO 4 films with high quality have been achieved via different methods [7][8][9].…”