Microstructure of the Pulsed Laser Deposited LaSrCuO Films

The X-ray diffraction and atomic force microscopy are used to examine the microstructure of La$\text{}_{1.85}$Sr$\text{}_{0.15}$CuO$\text{}_{4}$ films grown by pulsed laser deposition on LaSrAlO$\text{}_{4}$ substrates. The films grow with different degrees of built-in strain, ranging from a large compressive to a large tensile in-plain strain. The tensile strain cannot be attributed to a substrate-related strain. The possible origins of the tensile strain are discussed.