A similar crystallographic disorder, with an approximately 2-nm thickness, between the film and underlayer was shown in the perovskite LSMO and SrTiO3 epilayers grown on lattice mismatched
PND-1186 chemical structure materials [15]. This crystallographic disorder region is associated with a lattice strain relief between the film and the underlayer. The fast Fourier transformation (FFT) patterns in Figure 2d shows two misoriented nanograins. Depending on the relative rotation among the different grains during thin-film growth, the Selleck KPT-8602 subgrain boundaries are formed among the nanograins. The TEM image shows that the subgrain boundaries on the nanometric scale combine the discrete-oriented crystallites to form a continuous LSMO nanolayer. Quantization of the spectrum in Figure 2e shows that the contents of La, Sr, Mn, and O are approximately 12.45, 7.85, 22.11, and 57.59 at %, respectively, for the LSMO thin layer. Therefore, approximately 38.7 at % of Sr dopant was achieved within the LSMO. Figure 2f exhibits that the element contents of the In2O3 layer
are slightly oxygen deficient (the contents of In and O are approximately 46.19 and 53.81 at %, respectively). This is because the In2O3 epitaxy was Selleckchem Silmitasertib grown under an oxygen-deficient atmosphere. Figure 2 TEM and HRTEM images and EDS spectra of LSMO nanolayer and In 2 O 3 epitaxy. (a) Low-magnification TEM image of the LSMO nanolayer with In2O3 epitaxial buffering on the sapphire substrate. The HRTEM image was taken from the interface of the In2O3 epitxay-sapphire substrate (white oxyclozanide square region), and the inset shows the corresponding electron diffraction pattern at the heterointerface. (b) HRTEM image taken from the local single LSMO nanograin on the In2O3 epitaxy. (c, d) HRTEM images taken from the different local regions containing two neighboring LSMO nanograins on the In2O3 epitaxy. The corresponding FFT patterns taken from
the different oriented LSMO nanograins are also shown in the insets of (d). (e) EDS spectrum taken from the LSMO nanolayer. (f) EDS spectrum taken from the In2O3 epitaxy. Figure 3a shows the cross-sectional TEM morphology of the LSMO nanolayer grown on the bare sapphire substrate. A similarly damaged thin-layer was observed herein. Notably, granular LSMO layer contrast changes suggest that the film is composed of different LSMO crystallite orientations. Comparatively, the LSMO on the sapphire substrate experienced a relatively small degree of contrast changes, which cause the film structure to be more homogeneous than that on the In2O3 epitaxy. The insets show HR lattice fringes taken from different local regions at the interfaces between the LSMO nanograins and the sapphire substrate. Two types of heterointerface between the LSMO and substrate were presented. In the left inset, a thin (approximately 2 nm thick) transition layer formed at the heterointerface.