Difference between SEM and EDX analysis

Scanning Electron Microscopy (SEM) and Energy-Dispersive X-ray Spectroscopy (EDX) are two complementary techniques often used together for materials characterization. Here are the key differences between SEM and EDX analysis:

  1. Scanning Electron Microscopy (SEM):
    • Purpose: SEM is primarily used for imaging the surface morphology of specimens at high magnifications.
    • Methodology: In SEM, a focused beam of electrons is scanned over the sample’s surface. The interaction between the electrons and the sample produces various signals, including secondary electrons, backscattered electrons, and characteristic X-rays.
    • Imaging: SEM provides detailed, high-resolution images of the surface topography and morphology of the sample.
  2. Energy-Dispersive X-ray Spectroscopy (EDX):
    • Purpose: EDX is used for elemental analysis of a sample, providing information about the chemical composition.
    • Methodology: EDX is often coupled with SEM to analyze the characteristic X-rays emitted from the sample when it is bombarded with the electron beam. Each element emits X-rays at characteristic energy levels, allowing the identification and quantification of elements present in the sample.
    • Analysis: EDX produces spectra showing peaks corresponding to different elements present in the sample, allowing for qualitative and quantitative elemental analysis.
  3. Information Obtained:
    • SEM: SEM provides visual information about the surface features, morphology, and topography of a sample.
    • EDX: EDX provides information about the elemental composition of the sample, indicating which chemical elements are present and in what quantities.
  4. Application:
    • SEM: SEM is widely used in various fields for surface imaging, including materials science, biology, geology, and nanotechnology.
    • EDX: EDX is often used in conjunction with SEM but has broader applications in fields such as metallurgy, geology, forensics, and environmental science for elemental analysis.
  5. Output:
    • SEM: The output of SEM analysis is typically high-resolution images or micrographs.
    • EDX: The output of EDX analysis is an elemental spectrum showing the presence and intensity of characteristic X-ray peaks for different elements.

SEM is focused on providing detailed images of the surface morphology, while EDX is focused on analyzing the elemental composition of a sample. When combined, SEM and EDX offer a powerful tool for both imaging and chemical analysis of materials.

Find out more at our Scanning Electron Microscopy Analysis Laboratory