Electron Optic Documents

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.

SEM is an indispensable tool for studying the microstructure of a wide variety of materials. The images generated are inherently a 2 dimensional representation of the sample surface. Unlocking the 3rd dimension by reconstructing a 3D model from multiple SEM images can enhance our understanding of complex microstructure. This 3D view is often more intuitive and surface metrology characteristics can be calculated.

In this interview, AZoM speaks to Vern Robertson, EPMA Product Manager at JEOL USA, about the benefits of using a low kV in SEM imaging.

JEOL is always making efforts to meet the needs of our customers in all areas including hardware and software of our instruments. Our efforts to grasp customer requirements include question and answer opportunities during technical seminars and meetings. Based on these questions, we have published this Q&A book.

Tomographic and microED data sets created by SerialEM are single files with the data stored typically as 16-bit signed or unsigned integers. When these files have to be copied from the computer onto a USB drive, problems can arise.

What makes the difference between a good SEM image and a stellar one? Imaging samples at the appropriate conditions, and that often means at very low accelerating voltage (low kV). It's time to give it a try! Every modern day scanning electron microscope (SEM) from the top of the line, ultra-high resolution field emission SEMs to the most economical entry level bench-top tungsten (W) thermionic SEMs have the capability of imaging samples at very low accelerating voltage (Low kV ). Low kV imaging has many benefits and this easily accessible function should not be overlooked.

Cryo-EM has enjoyed an enormous ground swell in popularity ever since the advent of more stable and automated electron microscopes, suitable movie-type cameras, and improved acquisition software. Results obtained so far have been nothing short of spectacular as illustrated by several structures in EMDB and EMPIAR solved by cryo-EM to resolutions better than 1.5Å, such as EMD-31314, EMD-33707 and EMD-35984, the latter of which reaching true atomic resolution. This note describes the workflow used in Single Particle Analysis (SPA) cryo-EM workflows with the Osaka framework, i.e. a set of scripts that work with SerialEM.

Effortless sample navigation using JEOL’s Stage Navigation System (SNS). This system includes a high resolution, color CMOS camera mounted on the top of the SEM sample chamber, which captures a picture of the sample mounted on the stage. From this color picture, the user can control the position of the sample.

STEM-in-SEM (Scanning Transmission Electron Microscopy in an SEM) has become a popular technique for biologists, polymer scientists and materials scientists for its ease of use, cost effectiveness and high resolution. It is especially suited to investigating the internal structure of thin film (100-200nm) samples as well as size and shape of submicron to nanometer particles. With standard SEM imaging modes on bulk samples, there are limitations in the ultimate resolution that can be achieved due in part by the beam-sample interactions. With STEM-in-SEM, the sample is very thin and the interaction volume is small. Therefore, the resolution more closely approximates the diameter of the electron beam at the exit surface of the sample allowing for high resolution; using STEM with our state of the art FE SEMs, sub-nanometer resolution is easily achieved.