Transmission electron microscopy and high-resolution electron microscopy of growth defects in La2-xSrxCuO4thin films

AbstractPlanar defects extending through the whole film thickness have been observed by transmission electron microscopy in La2-xSrxCuO4(x= 0·15) thin films. Electron diffraction experiments on plan-view specimens showed that the defects were located in (101) or (011)-type planes. The defects have been analysed by high-resolution lattice imaging and their displacement vector determined using image processing. Possible origins for these kinds of defect are discussed and comparison is made with pure shear defects due to nonstoichiometry. Evidence for the presence of such pure shear defects, having a displacement vector R= 1/6[031], was indeed also given by the experiments. Models for the different kinds of defect have been developed.