Using a scanning electron microscope in physics STEM education

Abstract

This paper describes the use of a tabletop electron microscope in teaching college level physics. The workings and use of an electron microscope encompass many aspects of science, technology, engineering and mathematics (STEM). A sequence of activities was constructed to compliment the instructional material in the physics course of the University of Queensland Foundation Year. A Hitachi TM4000 scanning electron microscope was used to obtain images to measure the track spacing of CD, DVD and Blu-ray discs. The nominal track spacings are 1.6 µm, 740 nm and 320 nm for CD, DVD and Blu-ray discs, respectively, comparable to the wavelength of visible light and therefore give rise to visible diffraction effects. The track spacing for a CD and DVD was measured using red, green and blue laser pointers with an accuracy well under 10%. The experiments described in this paper demonstrate how a scientific instrument such as a scanning electron microscope can be used to integrate the teaching of different STEM areas.