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Atomic Step Organization In Homoepitaxial Growth On Gaas(111)B Substrates, Leo J. Schowalter, Kai Yang, Thomas Thundat

Scanning Microscopy

When homoepitaxial growth is performed on exactly oriented (singular) (111) GaAs substrates, while maintaining the √19 x √19 surface reconstruction, the originally flat surface spontaneously evolves vicinal (111) facets that are tilted approximately 2.5° toward the < 211 > azimuthal directions. These facets form pyramid-like structures where the distance between adjacent peaks can be varied from as little as 1 μm to tens of μm. When these surfaces are observed with atomic force microscopy (AFM), we find that they are extremely smooth with the observed tilt resulting from atomic steps which are spaced at approximately 7.5 nm. We have also studied growth on …

Balancing Surface Energy Terms For Stable Growth Of Planar Surfaces, M. Albrecht, P. O. Hansson, S. Christiansen, W. Dorsch, H. P. Strunk, E. Bauser

Scanning Microscopy

We investigate the driving forces that determine the growth mode of heteroepitaxial Ge layers grown from solution on Si substrates with orientations (001), (011) and (111) by transmission electron microscopy (TEM) and atomic force microscopy (AFM). Using liquid phase epitaxy, we can study the influences of strain and surface energy terms independently on effects due to limited surface diffusion. In (001) and (011) orientated layers, {111} faceted islands form (Stranski-Krastanov growth). In contrast, (111) orientated layers grow in a two-dimensional step flow growth mode (Frank-van der Merwe growth).

We model these investigations in terms of energy minimisation considering surface energy …

Electron Spectroscopy And Atomic Force Microscopy Studies Of Dna Adsorption On Mica, Carol E. Rabke, Lisa A. Wenzler, Thomas P. Beebe Jr.

Scanning Microscopy

Various methods for the deposition of deoxyribonucleic acid (DNA) molecules on mica are investigated to determine their reproducibility, and to quantify their ability to bind DNA. The use of these deposition methods for sample preparation for biological scanning tunneling microscopy (STM) and atomic force microscopy (AFM) studies is discussed. Auger electron spectroscopy (AES) and electron spectroscopy for chemical analysis (ESCA) were used to investigate the quantity of DNA adsorbed. AFM images of DNA deposited using the methods investigated are presented. The combination of AFM results with AES and ESCA results provides a basic understanding of the deposition techniques studied and …