Epitaxial growth of high quality La2CuO4 film on LaSrAlO4 substrate with introduction of ultrathin amorphous layer of La2CuO4

The authors present the apparent improvement of quality of La2CuO4 (LCO) thin films with the introduction of an amorphous layer (AL) of LCO. The samples were grown on LaSrAlO4 substrates by pulsed laser deposition. X-ray diffraction (XRD) measurements demonstrate that the introduction of the AL of LCO significantly improves the structural quality of LCO thin films. The linewidth of XRD peaks is significantly narrowed down to 129 arcsec. Atomic force microscopy (AFM) shows that the surface precipitates are sufficiently suppressed for the LCO films with ALs. The spectra of optical absorption indicate that the ALs can improve the stoichiometry of the LCO films. The mechanism for the improved quality of LCO films with the ALs is discussed based on the results of XRD and AFM measurements.