RESUMO
The surface characteristics of a large set of commercial lightweight coated paper grades are explored. The quantification of the 3D structure is revealed by atomic force microscopy, laser profilometry and X-ray microtomography. This comprehensive study demonstrates the suitability of different and modern methods for assessing critical coating layer properties, thus identifying the right tools for specific structural analyses. Based on the assessment of the top and bottom surfaces of 25 commercial lightweight coated samples, three main conclusions can be drawn: (1) the facet orientation polar angle is a function of roughness, (2) skewness did not describe the surface details affecting the gloss of the commercial lightweight coated samples assessed in this study and (3) surface roughness at wavelengths below approximately 1.0 microm does not affect the paper gloss significantly. This is important knowledge for the understanding of lightweight coated paper surface structure and its properties.
RESUMO
The Sb concentration in axial GaAs(1-x)Sb(x) inserts of otherwise pure GaAs nanowires has been investigated with quantitative high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM). The Sb concentration was quantified by comparing the experimental image intensities normalized to the incident beam intensity with intensities simulated with a frozen lattice multislice approach. Including static atomic displacements in the simulations was found to be crucial for correct compositional analysis of GaAs(1-x)Sb(x). HAADF intensities of individual nanowires were analysed both across the nanowires, exploiting their hexagonal cross-sectional shape, and along the evenly thick central part of the nanowires. From the cross-sectional intensity profiles, a decrease in the Sb concentration towards the nanowire outer surfaces was found. The longitudinal intensity profiles revealed a gradual build-up of Sb in the insert. The decrease of the Sb concentration towards the upper interface was either gradual or abrupt, depending on the growth routine chosen. The compositional analysis with quantitative HAADF-STEM was verified by energy dispersive X-ray spectroscopy.