Journal of Student Research 2013

169

Electron Microscopy Images Reveal Magnetic Properties

Method

Step 1 First, we drew lines along rows of atoms and measured the perpendicular distance across them. Step 2 Next, we took the FFT of the image and hovered our cursors over bright spots in Image J, revealing the real-space distance between the corresponding planes. Step 3 Finally, we looked at the plot profile– Image J creates an intensity vs position plot from which peaks can be counted and measured– for each image. Figure 8

Figure 8: Plot vs. Intensity graph of an HRTEM image of a nanomagnet using ImageJ.

Since materials are 3-dimensional, there are many planes that cannot be drawn without multiple images from different angles of the particles. Planes are most often described by a set of three values which describe vectors in 3D space. These vectors identify three points which then form a plane. Almost any plane drawn through a homogeneous sample will yield a repeating