Electron Optic Documents

OBF System - Live Low Dose, Light Element Imaging

Wet specimens are notoriously difficult to image in scanning electron microscopes (SEM) owing to evaporation from the required vacuum of the specimen chamber. Traditionally, this issue has been addressed by increasing the specimen chamber pressure. Unfortunately, observation under high specimen chamber pressure cannot prevent the initial evaporation effects. The wet cover method, where the original surface water is retained (and, therefore, considered wet), provides a way to introduce and subsequently image specimens that are sensitive to evaporation within a SEM, while preventing evaporation-related damage, and to observe interesting specimen–water interactions.

JEOL’s Particle Analysis Software 3 (PA3) enhances the capability of your analytical SEM by automating the detection, EDS analysis and classification of particles, grains or other features in your samples. Fully integrated with our SEM-EDS systems, PA3 increases throughput and productivity by providing fast, unattended measurements across large areas of a sample, or multiple samples.

Phase Analysis provides a new level of automation to your JEOL EDS data analysis and interpretation workflows

When a sample is exposed to the electron beam in a scanning electron microscope a variety of signals are generated. X-rays being one of those signals that can provide valuable insight into a materials chemical makeup. The collected X-ray signal includes background X-ray radiation and more importantly, X-rays of specific energies, that are characteristic of the elements present in the sample. For this reason, an energy dispersive X-ray detector (EDS) is one of the most common detectors that is added to a scanning electron microscope (SEM). It is used to not only determine the elements present in a sample but in many instances can give insight to the quantity as well as the spatial distribution of these elements over very small volumes.

The IDES Relativity Electrostatic Subframing System multiplies the frame rate of cameras on JEOL TEMs. Microscopes equipped with Relativity achieve exceptional time resolution, data throughput, and advanced automation capabilities. Addition of Relativity allows current JEOL TEM users to forego expensive camera upgrades to their existing systems, instead relying on installation of an electrostatic optics assembly in a wide-angle camera port. These optics rapidly deflect the image data to different regions (subframes) of the camera in a programmable sequence. Each camera readout contains a tiled array of crisp, blur-free subframes. Raw data is automatically analyzed to give a stack of open format images that are loaded back into the camera control software for viewing or further analysis.

The first commercially available SEM was introduced over 50 years ago and to this day there is still no internationally accepted standard for determining SEM resolution. To add to the confusion, each SEM manufacturer relies on their own sample and methods for determining resolution.

The first commercially available SEM was introduced over 50 years ago and to this day there is still no internationally accepted standard procedure for determining the resolution in an SEM image. To add to the confusion, each SEM manufacturer relies on their own sample and methods for determining resolution. Defining the edge of a particle manually is also always subjective in nature; values will differ from one person to the next based on how that person interprets or ‘sees’ the edge of a particle.

Since the Scanning Electron Microscope (SEM) was first commercialized about 40 years ago, the SEM has shown a remarkable progress. Now, many types of SEMs are being used, and their performance and functions are greatly different from each other. To utilize these different SEMs, it is essential to recognize their features, as well as to understand the reasons for the contrast of SEM images. Thus, this document material is aimed at helping SEM users and future SEM users to understand the basics of the SEM, including the instrument principles, specimen preparation and elemental analysis.

SEM images are often displayed as a 2D view or projection of a 3D specimen, which could be often frustrating for researchers who are interested in uncovering the topography features that are in the ‘hidden’ 3rd dimension.


Other Resources

  • Image Gallery
    View a selection of electron images
  • FAQs
    See answers from questions often asked about our SEM and Surface Analysis instruments
  • Links & Resources
    View our page of useful and interesting links to various electron microscopy resources
  • Videos
    View some product presentations of our instruments
  • SEM Theory and SEM Training
    Learn about basic theory, physical operation, and practical applications for SEM
    Basics of SEM
    Learn about the basics of scanning electron microscopy
    JEOLink Newsletter
    Several times a year, we publish and send out a newsletter to our customers. They can also be viewed here
    © Copyright 2023 by JEOL USA, Inc.
    Terms of Use
    Privacy Policy
    Cookie Preferences