Epitaxial growth of Gd2-xCexCuO4 thin films

Abstract

We have grown (001)-oriented thin films of Gd2-xCe xCuO4with cerium composition 0 < x < 0.2 by state-of-the-art reactive molecular beam epitaxy and characterized them by x-ray diffraction and transport measurements. A systematical change in the c-axis length upon cerium doping indicates that single-phase films were obtained for the whole doping range. Based on a log po2 - 1/T phase diagram in combination with reflection high energy electron diffraction (RHEED), phase stability has been determined in order to achieve optimized reduction conditions. Gd2-xCexCuO4 thin films even after controlled reductions treatment did not show superconductivity in the whole range of Ce concentration studied. However, the room temperature resistivity of optimally reduced Gd2-xCexCuO4 thin films shows a minimum at around xCe 0.16. Our results on the growth and characterization of Gd2-xCexCuO4 thin films on (100) SrTiO3 substrates are described in detail. © 2008 IOP Publishing Ltd.