Imaging magnetic and non-magnetic metal nanostructures using a field emission SEM.

An electron microscope can be used to image materials of nanoscale dimensions allowing for examination of size and shape characteristics, and chemical composition. We use an FEI Apreo scanning electron microscope to image magnetic (using electromagnetic mode) and nonmagnetic nanostructures (using electrostatic mode) of various metals (Au and Ag) and metal alloys (Fe/Co, Fe/Au) using different sample preparation methods, and varying system parameters for optimal image quality and resolution. Samples are prepared with spin coating followed by plasma cleaning, with controlled plasma composition. System parameters of spot size and accelerating voltage for different built-in detectors (ETD, EBSD, in-column BSD detectors, and STEM) are studied. Methods for obtaining optimal EDX maps are also investigated, as EDX is prone to sample charging and image drift due to extended exposure of the sample to the electron beam. Details of the imaging parameters and sample preparation for these nanostructures will be presented.