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Frequently Asked Questions: Meet our newest SEM
What is the depth of investigation range?
The Axia ChemiSEM maps the sample's elemental composition using Energy-Dispersive X-ray Spectroscopy (EDS). The resolution (X, Y and depth) is dependent on the material type (heavy or light elements) and settings of the microscope (acceleration voltage) but is typically in the range of 1 micrometer.
If the EDS is quantitative, how much is the error percentage? Do we standardize the elements all the time?
EDS quantification typically comes with errors of a couple percent. The Axia ChemiSEM uses a standardless quant algorithm.
How much does the Axia ChemiSEM cost?
Axia ChemiSEM is very competitively priced. In order to find out pricing for the configuration that best meets your specific needs, please get in touch with a local Thermo Fisher sales person or leave your contact details in the form at the bottom of the Axia product page.
Can the EDS system detect lithium?
For lithium detection it is typical to use a higher class of instrumentation (Apreo SEM for example) with a dedicated WDS or windowless EDS system. That said - the Axia does offer the ports to accommodate a wide range of accessories, including ones for lithium detection.
Is the user able to assign fixed colors for elements?
Yes, that is possible. During live elemental mapping, the Axia ChemiSEM automatically assigns colors to the elements that are found in the sample, and it picks colors that provide good contrast. A "refresh" button allows you to cycle through color schemes, which lets you easily select a scheme that you like the most. But it is always possible to manually assign colors and keep them fixed for a particular element.
Does Axia ChemiSEM work with biological samples?
Yes. There is a wide range of biological samples, and it depends on the sample type (sensitive, wet, insulating, feature size, etc.) and sample preparation (dried, resin embedded, frozen, etc.) which instrument is most suitable. For a large range of samples, Axia ChemiSEM will provide you with excellent imaging and analytics. Please let us know your specific needs and we can put you in contact with an applications specialist.
Is the color density linked to the concentration of a particular element?
Yes. The color saturation is proportional to the concentration of that particular element. There are sophisticated normalizations behind the display of the colors, so that small features are still visible, even when there is a strong background.
Is there an option to stop EDS once the element of interest and quant criteria is met?
Yes. The parameters for point / area / line acquisitions allow setting termination criteria such as X-ray counts or number of seconds.
Can only the EDS maps be colored? Or can SE and BSE images be colored as well?
There are several ways in which we can color the SEM images - EDS being one. The Axia ChemiSEM also lets you assign separate colors to SE and BSE signals, which are then automatically mixed. Finally, there is an optional cathodoluminescence detector which will provide real color images. If you want to manually colorize SE images, that is possible with our TopoMaps software.
Does the Axia ChemiSEM work on uncoated, non-conductive samples? What is the EDS spatial resolution on these samples?
Yes, imaging, EDS and live quantitative elemental mapping work on uncoated, non-conductive samples - it requires working in low vacuum mode. In low vacuum, there is water vapor in the chamber which neutralizes charge on the sample surface. The SEM imaging resolution (and hence EDS imaging resolution, typically 1 um) is hardly affected by low vacuum. However, the small amount of electron beam scattering will excite elements from a broader region, introducing additional peaks in the EDS spectrum. This will have to be considered when interpreting the results.
What is the chamber pressure in low-vacuum mode? Is the column differentially pumped?
The Axia allows a chamber pressure up to 150 Pa, and yes, the column is differentially pumped.
What is the size of the detector?
The detector is placed relatively close to the sample, and as such the detector area is not the best measure of its sensitivity. We offer detectors with solid angles ranging from 13 mSr to 38 mSr.
Will the EDS detector deteriorate faster if you use ChemiSEM more often?
In short: no. In general, it's true that materials can deteriorate if you expose them to X-rays. However, the number of counts that an X-ray detector can handle before it noticeably deteriorates is orders of magnitude larger than what it would receive in the typical lifetime of a SEM-EDS system.
Does Axia ChemiSEM work with non-conductive samples?
Non-conductive samples are a challenge, however, the Axia does have an option for low-vacuum analysis. This means we inject a small amount of pressure in the chamber in the form of water vapor. This alleviates charge and permits imaging of the conductive surface. Low Vacuum mode also allow working at accelerating voltages appropriate for EDS analysis. While there are additional artifacts that can be induced due to the physics of particle interaction, it is still possible to obtain meaningful EDS data. Of course, if the sample can be coated, and not impact the EDS results, that can be used as a mitigating factor as well.
How similar is the Axia ChemiSEM to the ColorSEM option in the Thermo Scientific Quattro ESEM?
Axia ChemiSEM will come with a more advanced EDS package, including an offline version that will replace most fundamental EDS functionality for online and offline analysis.
What are the imaging modes in low vacuum?
All imaging modes, BSE, SE, EDS, CL are available in Low Vacuum on the Axia ChemiSEM.
Can the Axia ChemiSEM be added with FTIR analysis?
Our Maps software has an option for correlative microscopy. If you have spatial FTIR data, those data can be imported into the Maps platform and aligned with the imagery acquired on the Axia. Allowing you to integrate observations of the different techniques.
How much time will it take for a user to be completely adapted to using ChemiSEM? Is there a training program or course available?
The Axia ChemiSEM was designed for new users. The system has new advanced auto functions that manage the alignment, focus and mitigating the aberrations that are typically the most difficult for new uses to deal with. In addition, the Axia ChemiSEM has user guidance built into the UI. Users only need to know what sample type they have (or what workflow they want to follow if they have a bit more experience) and User Guidance will walk the user through, and directly operate the system, to aid users in getting started. In addition, the single button approach of our integrated EDS makes analytics incredibly approachable and requires no additional instruction on a different user interface. In practice, with just a brief introduction, users should feel confident in operating the system due to all the automation and built in help aids.
On Axia ChemiSEM is it possible to work with other detectors like EBSD and WDS? Is the Axia ChemiSEM compatible with MAPS Mineralogy?
Axia ChemiSEM comes with all the standard ports for adding additional detection technology. EBSD, additional EDS detection and WDS are all supported by Axia. At launch, Axia will not support Maps Mineralogy.
What is the focal area for EDS? How does real time machine learning help the ChemiSEM work?
The viewable area for EDS in the Axia ChemiSEM is the same for traditional imaging. While Axia ChemiSEM does use machine vision algorithms as part of the image analysis protocols built into the technology, the approach is not classified as ML in the traditional sense. More insight into how this works can be learned in our dedicated Whitepaper on the LiveEDS imaging we have implemented on the system.