Structural analysis of infinite layer superlattices grown by pulsed laser deposition

In this work we investigate the structural properties of SrCuO2/CaCuO2 infinite layer superlattices by high-resolution x-ray diffraction and x-ray specular reflectivity measurements. The infinite layer superlattices are grown by pulsed laser deposition on slightly misoriented (001) SrTiO3 substrates. We demonstrate that good quality superlattices with few monolayers thick constituent SrCuO2 and CaCuO2 layers can be grown having an interface roughness of less than 3-4 Å. A strain analysis of the epitaxial film shows that the SrCuO2 layers are completely relaxed with respect to the substrate. However, the CaCuO2 layers are elastically strained with respect to the SrCuO2 layer. The Poisson ratio of the CaCuO2 is estimated to be 0.40±0.08.