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In this work, we report on the impact of distinct growth parameters that affect the roughness and surface morphology of La2/3Ca1/3MnO3 epitaxial thin films grown by rf sputtering, namely, the film thickness and the deposition temperature. Data for films with thicknesses ranging from 2.4 to 108 nm will be presented. A correlation with transport measurements is also reported: whereas films thicker than 6 nm show the typical metal-to-insulator transition, the thinner film is insulating. The resistivity is strongly enhanced when decreasing film thickness. Nuclear magnetic resonance measurements have been used to monitor the relative concentration of the localized Mn4 + and delocalized Mn3+/4 + states. It is found that the relative intensity of the delocalized Mn3+/4+ configuration (I3+/4 + ) progressively lowers when reducing film thickness. Of significance could be the observation that I3+/4 + remains finite for the thicknesses corresponding to insulating films, thus suggesting that an electrically inhomogeneous state is formed in a region close to the interface with the substrate.

As a scalar wave is incident upon a rough surface at grazing angle, the Helmholtz wave equation can be approximated by the parabolic equation. Inverse scattering has been formulated in the form of a pair of coupled integral equations in two unknown functions, i.e., surface current and surface roughness. The aim of this article is to implement this approach for profile reconstruction of complex fractal rough surface. The fractal rough surfaces described by a band-limited Weieztrass-Mandelbrot function are numerically realized using the Monte Carlo method. As the scattering fields along a line parallel to the mean surface are measured or solved with a scalar wave incidence at low grazing angle, the rough surface profile is progressively inverted. Numerical examples show that the reconstructed profile and its parameters such as the fractal dimension, roughness variance, and correlation length are well matched with the simulated surfaces.

Molecular dynamics simulations are performed to study the fundamental role of the ion beam in determining the in-plane texture of <100> oriented (out-of-plane) MgO films during ion beam assisted deposition (IBAD). Sputter yields are determined as a function of in-plane orientation for Ar ion beams. The minimum sputter yield exists at an ion beam orientation corresponding to the MgO <110> direction. The finite width of the sputter yield minimum is attributable to two main factors: (i) only a fraction of the incident ions are oriented to travel directly down the center of the channel and (ii) ions that are not exactly parallel to the channeling direction may channel. While the simulations imply that it is possible to in-plane orient {001} MgO films using IBAD, there are fundamental limitations on the degree of ordering that can be achieved.

The Si + and O + signals, as obtained in secondary ion mass spectrometry (SIMS) analysis of silicon when using oxygen as the primary species, pass through an initial transient region before reaching the stationary state. We simulate this transient zone to check a phenomenological model for the secondary ionization of sputtered atoms. The simulation is split into two parts: the sputtering of neutrals obtained from implantation, sputtering, relocation/replacement, and diffusion, simulations and their subsequent ionization. The ionization phenomena are also described by some ad hoc fitting functions with which the SIMS measurements are better approached than with the model. The fitting functions and the model outputs are verified with experimental secondary ionization data.