Scanning electron microscopy is an incredibly useful and reliable tool for many industries to use. However, it’s not always clear what this method is and how it works. Below, you can find a lot of information about this method and why it’s so good:
What is Scanning Electron Microscopy?
An SEM (scanning electron microscope) is a tool that scans an electron stream over a surface. The electron stream is scanned and focused in order to create an image. The electrons that are beamed onto a particular surface start to interact with any surface they come into contact with. When this happens, a range of signals is produced. These signals allow the user to obtain a few details about the surface in question’s composition and topography.
When a surface’s composition and topography are understood, more information about the surface can be used. This is information that may have otherwise gone unnoticed in the past and through the use of other methods.
Used Instead of a Microscope
Many people choose to use scanning electron microscopy services instead of a microscope. This is because modern microscopes can only magnify a surface up to 1,000 times. In addition to this, the microscope is fairly limited as it uses a very limited number of wavelengths. For example, white light has a range of approximately 400-700 nanometers. However, the average wavelength is 550 nanometers. What this means is that there is a theoretical limit that isn’t visible. Users may, therefore, have to guess what the theoretical limit could have otherwise shown.
Electron microscopes tend to be used instead of a traditional microscope as the electrons have shorter wavelengths. What this means is that a better resolution is given. In other words, more detail can be seen and better judgments can be made.
How Electron Microscopy Works
Scanning electron microscopy works to produce electrons at the top of the electron gun. The electrons are then sent down the gun and they pass through a range of lenses and a few apertures. This takes place in order to focus a beam of electrons on a surface. When the surface is hit by the beams, the surface is penetrated by a few microns. This enables the scanning electron microscope to receive more information about the surface in question.
The electrons produce what is known as “secondary electrons”, x-rays, and back-scattered electrons. The signals are automatically collected by at least one detector and form images. These images are displayed on a screen.
Some scanning electron microscopes are able to achieve a resolution of less than 1 nanometer. However, many offer between 1 and 20 nanometers.
As you can see, scanning electron microscopy is a very useful tool. It can be used across a range of industries and provide more data than would otherwise be found. Industries such as the pharmaceutical industry, defence, electronics, mining, law, data storage, and the aerospace industry can benefit from this type of high-resolution imaging. It’s no wonder then, that more and more people are opting to use this reliable method.