Quantifying the shape of nanoparticles: Segmentation and elongation measure

Abstract

The influence of the shape of nanoparticles on the magnetic properties of nanoparticle materials is often mentioned, but is not much studied in literature. In order to better understand the magnetic properties of nanomaterials a very important step is to measure shapes using the shape descriptors. As one of the most common descriptors, the elongation measure of nanoparticles was used, while experimental results were obtained using TEM images of hematite. With the goal of shape analysis the images were segmented to produce isolated nanoparticles and after that the elongation of separated nanoparticles was measured. The elongation measure ε(S) proposed and used in the experiment gives intuitively expected results. On the opposite, it has been pointed out that, like all other shape descriptors ε(S), besides the undoubted advantages, there are certain disadvantages. Therefore, it is proposed to use several different descriptors, which provide better and more precise characterization of nanoparticles, which can avoid the flaws that some descriptors have.

Keywords

• shape analysis
• nanoparticles
• elongation
• shape descriptors
• segmentation