Scanning Electron Microscope and Energy Dispersive Spectrometer

Houston Electron Microscopy is equiped with a State of the art SEM/EDS system with many features, such as variable pressure,  secondary and backscatter imaging, x-ray mapping, particle analysis, and elemental analysis of anything viewed under the SEM. SEM/EDS analysis can identify those microscopic particles or contamination causing process problems.

SEM/EDS Imaging

Houston Electron Microscopy, Inc. is equipped with JEOL JSM-6360LV Scanning Electron Microscope, A fully digital Scanning Electron Microscope, capable of usable magnifications of up to 100,000 times in Secondary Imaging mode with 3.0-nm resolution for topographic imaging.

Imaging Features:

• Topographic Imaging
• Atomic Number Profile Imaging
• Elemental X-ray Mapping
• Image Segmentation

Three modes of Backscattered Electron imaging also provide atomic number contrast and topographical imaging in high and low vacuum modes. High vacuum imaging provides the highest resolution at 3.0 nm. Typical observations are performed at magnifications in the range of 1000x to 10,000x, but magnifications as high as 100,000x can be obtained.

Allowing a small amount of air into the chamber (Low Vacuum mode) neutralizes charges on uncoated, non-conducting materials so that gold coating is not required for plastics, ceramics, and other dielectrics. Max sample size: 4 inches dia. x 2.5 inches high.

Here is an image of a mite found in moss. The image was taken at a magnification of 350x, without any gold sputtering. The head of this little guy measured approximately 50-microns or 0.050 millimeters.

Secondary Electron Imaging

Secondary electron images show the morphology and topography of a sample. The most common form of imaging, Secondary Electron Imaging (SEI) produces a high resolution image of the surface topography of a specimen. In failure analysis, this usually provides enough information to determine the mechanism of failure of a material. The SEM provides several advantages over light microscopes including greater magnification, greater depth of field, and finer magnification control. See more.

Backscattered Imaging

Back scattered electron images show the difference in atomic number over a sample. The higher the atomic numbers of the atom, the brighter the image results for larger atoms. See more.

Secondary Electron Imaging

 

Backscattered Imaging

 

 

Three modes of Backscattered electron imaging are available in high or low vacuum modes at 4.0 nm resolution:

• Compo (for Composition): Atomic number contrasting imaging. Lighter elements appear darker while heavier elements appear brighter.
• Topo (for Topography): Surface topography imaging similar to Secondary Electron imaging
• Shadow: Combination of Compo & Topo with illumination from the side.

X-ray Mapping

Houston Electron Microscopy’s is SEM is equipped with a state-of-the-art integrated an IXRF System Energy Dispersive Spectrometer (EDS). Using the latest SDD technology and an ultrathin window, elemental data from Beryllium (Z=4) through Plutonium (Z=94) is collected at extremely high rates for elemental analysis. Additionally, built-in software allows for stoichiometric calculations of compounds present such as oxides, carbides, etc.

Typical EDS Spectrum

Typical EDS (or EDX) spectrum showing how characteristic X-rays correspond to different elements.

Elemental X-ray Map

Elemental X-ray map of Carbon, Iron, and Oxygen mapped onto a nodular cast iron fracture. The red spheres are nodules of graphite (carabon) in a matrix of iron (blue). Oxygen is set as yellow, so rust, FE₂O₃, appears greenish.

Elemental and compound information can be viewed in several formats including elemental spectrums to identify the elements present, quantitative atomic and weight percent calculations, and x-ray mapping that combines the image with its chemical composition as shown above.