Manipulating composition gradient in cuprate superconducting thin films

The techniques of growing films with different parameters in single process make it possible to build up a sample library promptly. In this work, with a precisely controlled moving mask, we synthetized superconducting La2-xCexCuO4+/-{\delta} combinatorial films on one SrTiO3 substrate with the doping levels from x = 0.1 to 0.19. The monotonicity in doping along the designed direction is verified by micro-region x-ray diffraction and electric transport measurements. More importantly, by means of numerical simulation, the real change of doping levels is in accordance with a linear gradient variation of doping levels in the La2-xCexCuO4+/-{\delta} combinatorial films. Our results indicate that it is promising to accurately investigate materials with critical composition by combinatorial film technique.