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Magnetic force microscopy was used to image and detect ferritin proteins and the strength of the magnetic signal is discussed, revealing a large workable lift height between the magnetic tip and the ferritin sample.

The self-assembled GaN hexagonal micropyramid and microdisk were grown on LiAlO2 by plasma-assisted molecular-beam epitaxy. It was found that the (0001¯) disk was established with the capture of N atoms by most-outside Ga atoms as the (1×1) surface was constructing, while the pyramid was obtained due to the missing of most-outside N atoms. The intensity of cathode luminescence excited from the microdisk was one order of amplitude greater than that from M-plane GaN.

Aminopropylsilatrane (AP-silatrane) was investigated as an adhesive layer for anchoring Au nanoparticles on silicon substrates. We compared the preparation procedure and film quality of the AP-silatrane films to those of 3-aminopropyltriethoxysilane (APTES), which is commonly used for nanoparticle attachment on silicon. The films were characterized by Fourier Transform infrared (FTIR) spectroscopy, contact angle measurements, and atomic force microscopy (AFM). The process for preparing the AP-silatrane films was much easier and resulted in more reproducibly high quality films due to its insensitivity to water. In surface roughness measurements, we observed a 39% increase (99 pm RMS) for the AP-silatrane film over that of a plasma-cleaned silicon sample (71 pm RMS). In contrast, we observed a 218% increase (226 pm RMS) for the APTES film. The much higher roughness observed for the APTES film was due to its sensitivity to water, which results in molecular aggregate formation and polymerization. Gold nanoparticles (7.5 nm) were deposited and firmly anchored to both types of film surfaces. The measured height of the particles on the films was less than the actual size of the particles, and plasma treatment was used to remove the organic layer, resulting in a corrected measurement of the particle size. AP-silatrane offers an easy preparation procedure that creates a smooth, aggregate-free adhesive layer for anchoring Au nanoparticles strongly to silicon substrates.

The surface morphology of GaN epitaxial films grown by plasma-assisted molecular-beam epitaxy has been investigated. We found that the surface morphology was sensitive to the N to Ga flux ratio (N/Ga) when grown at a high temperature (i.e., 788 °C). At that temperature, we did not observe large sized Ga droplets on the surface even at Ga-rich conditions. Furthermore, we found a transition from two-dimensional (2D) to three-dimensional (3D) growth in the intermediate Ga-stable regime. The slope of the growth rate was different: Slope=(0.39±0.06) was observed in the 2D-growth mode and (0.14±0.03) in the 3D-growth mode. In the high N/Ga ratio, the total dislocation concentration was reduced, and the mixed threading dislocation concentration had a minimum value at N/Ga=22.5. By comparing with the Hall carrier concentration results, we found that the mixed threading dislocations influence the number of electronic carriers.

Insulin fibrils were used as a biotemplate for creating gold nanoparticle chains on glass substrates, and then subsequently removed by exposing the samples to a low-pressure plasma, leaving the gold nanoparticles on the glass surface in their template positions.

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