(Color online) (a) RSI oscillations of LNO/LAO SL (n ≈ 6) grown at T = 730 °C, mTorr and with a laser power density J/. Continuous deposition with a laser frequency of 3 Hz. (c) Interrupted growth with a frequency of 30 Hz and a dwell time ∼100 s. Insets: (a, c) RHEED patterns and (b, d) corresponding AFM images.
(Color online) (a) The slow intensity decay along the extended specular (00L) x-ray diffraction rod demonstrates the highly ordered nature of the surface and interface of the superlattice film structure. The interference fringes verify the strong coherent layered epitaxy of the film. (b) Presents an in-film-plane (HK) reciprocal space map of the (222) reflection showing the fully in-plane lattice constraint to that of the (001) substrate.
(Color online) (a) T-dependence of the RSI during the unit cell growth. The arrows indicate the start, tS and the end, tE of the ablation. The lowest diffracted intensity is marked as tM . The circles (left to right) correspond to , 0.5, and 0.7 coverage, θ. (b) AFM scans (1 1 μm2) obtained by interrupting the growth at the corresponding coverage. Since the evolution of disorder configuration during stage 1 is independent of temperature, the laminaelike pattern is roughly representative of the same surface seen by RHEED. Insets show the magnified false colored phase-contrast images.
(Color online) Timing diagram showing the modulated flux and relaxation of the island density (adapted from Ref. 15). During the low-frequency pulsed growth (a) the physical vapor is delivered to the substrate surface where it is relaxed. After increasing the pulse rate (b) the nucleation process becomes more and more delayed. As the frequency (c) reaches the quasiconstant state with average flux, the large degree of supersaturation overcomes the nucleation barrier resulting in the rapid nucleation from the supercritical vapor.
(Color online) (a) Temperature evolution of surface coverage, and (b) corresponding layer roughness, Δ. The stages of growth marked as 1–3 correspond to the same time intervals in Fig. 3(a). Note, the difference between the minimum and maximum of RSI is normalized to unity.
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