EDS

Turning quantification of lithium from days to minutes of work

Dr. Shangshang Mu, Applications Engineer, Gatan/EDAX

Cipher®, the quantitative analysis of lithium system, is a shining example of the synergies brought about by the merger between Gatan and EDAX. As an application specialist involved since the beginning of this project, witnessing the evolution of the data acquisition and analysis workflow is nothing short of astounding. I vividly recall those initial moments when we tested this concept and generated our first Li measurements from an actual sample.

I conducted energy dispersive x-ray spectroscopy (EDS) data acquisition and analysis in the EDAX APEX™ software during those early stages. At the same time, my colleague focused on the quantitative backscattered electron (qBSE) work within the DigitalMicrograph® software. To analyze the lithium content in a sample from just a few locations was a painstaking process requiring the laborious process of correlating information from disparate software programs manually, checking again and again that the same area of the sample was being analyzed, and then calculating by hand the lithium content of an analysis location using a variety of different mathematical models to determine the best one.

With the release of DigitalMicrograph 3.6.0, the entire data acquisition and analysis workflow unfolds seamlessly, marking a significant advancement in efficiency and user-friendliness, not to mention making my job so much easier! A guided workflow allows a user to conduct the whole experiment using a single software package. Using the Technique Manager, data acquisition and analysis happen step-by-step as you progress from the top palette to the bottom (Figure 1).

Li quantification-related palettes within the DigitalMicrograph Technique Manager panel.

Figure 1. Li quantification-related palettes within the DigitalMicrograph Technique Manager panel.

Several steps used to be challenging experimentally, which the software now manages for you, including:

  • Ensuring that the backscattered electron signal was calibrated by atomic number (Z) and, importantly, that there were no changes to the calibration when moving between samples
  • That data that was captured sequentially could be aligned and transformed before the lithium content being calculated
  • Use of the latest models for qBSE and EDS analysis methods

For the first challenge, appropriate Z-standards are required, and the detector settings and collection geometry must remain constant between qBSE measurements. The qBSE Calibration palette (Figure 2) provides intuitive guidance through this essential process, and when using the Z-standards provided with the system, what used to take an hour or more to complete can now be done in minutes. The buttons of the qBSE calibration palette guide you through the detector setup and measurement of the Z reference samples, populating the calibration table as you go. A calibration curve can be plotted for your reference once a minimum of four reference values are acquired. Vitally, the software continuously verifies that you are at the correct working distance for qBSE. If a measurement is attempted using incorrect conditions, qBSE data cannot be generated. Furthermore, the QuickSet button becomes active, allowing the user to launch a wizard that returns the system to the appropriate conditions for qBSE analysis. This has proven invaluable for many of the customer specimens I have analyzed, as they come in all shapes and sizes!

Figure 2. qBSE Calibration palette and an example of the calibration curve used for converting BSE signals measure to atomic number.

For samples analyzed in the SEM, DigitalMicrograph 3.6 now uses the same standardless EDAX eZAF method for analysis as APEX EDS Advanced software, enabling quantified EDS measurements to be performed reliably in the same software program as used for qBSE data collection. However, to ensure that the analyzed volume is consistent between the two methods, we typically collect data for the two signals at different accelerating voltages. Previously (e.g., [1]), the complexity of registering and aligning the qBSE and EDS data was too challenging to even attempt to map the lithium distribution, with researchers instead choosing to analyze a few isolated points only.

The Cipher Analysis palette (Figure 3) simplifies the process of correlating EDS and qBSE datasets like never before, enabling lithium content to be mapped over a 2D area or 1D line scan in addition to point analyses. By simply selecting the BSE and EDS workspaces from the dropdowns and clicking on the Align button, qBSE and EDS data captured under different conditions will be automatically registered and aligned using the corresponding secondary electron images; this alignment procedure even works if the qBSE and EDS data is captured at different magnifications or pixel density.

Figure 3. Cipher Analysis palette.

Subsequently, pressing Map Low Z will generate Li maps effortlessly using the latest algorithms in EDS and qBSE analysis (Figure 4), adjusting the original elemental maps to include the Li content.

Figure 4. Lithium map (in atomic percent) of a nickel manganese cobalt oxide (NMC) sample commonly used as a cathode material in the construction of lithium-ion batteries.

Looking ahead, the streamlined workflow in DigitalMicrograph and the continued evolution of Cipher promises to revolutionize lithium analysis, empowering researchers with unprecedented insights into battery technology, energy storage, and many other fields. I’m excited to be able to be involved with the development and release of a product that turns what was once impossible into a straightforward experiment.

Sometimes, you don’t know what you’ve been missing until you find it

Dr. Leslie O’Brien, SEM Manager, Lehigh University – Institute for Functional Materials and Devices

As a manager of an electron microscopy facility with a dozen instruments and a diverse user base, we often find ourselves heeding the adage, “If it ain’t broke, don’t fix it,” particularly when it comes to the ever-evolving field of energy dispersive x-ray spectroscopy (EDS) and electron backscatter diffraction (EBSD) software. With many instruments to operate and maintain, priorities and funding can shift unexpectedly. Upgrading EDS/EBSD software will likely get pushed to the back burner, especially when there is nothing functionally wrong with our version.

We recently had the opportunity to upgrade the EDAX computer on our focused ion beam (FIB) from TEAM™ to the new APEX™ software. The FIB does a substantial amount of EBSD work, with lesser EDS, and is one of our facility’s busiest instruments among academic and industry users. Of course, sometimes, with progress comes resistance! Users become comfortable and proficient with software or hardware and are frustrated or reluctant about spending the time and energy to learn something new.

Figure 1. EDAX EDS and EBSD systems running APEX software in the SEM lab in the Institute for Functional Materials and Devices at Lehigh University.

The transition from TEAM to APEX was, for the most part, an easy one. APEX has much of the same fundamental functionality of TEAM, with some nice additions, only minor restructuring, and an updated user interface (UI) that was a welcome sight.

Our facility serves researchers across all disciplines with various levels of analytical experience. We provide a mix of paid service research and hands-on training for users wanting to develop their own microscopy skill set. I have found that APEX’s updated, user-friendly interface has made the training aspect easier for both the teacher and the student. We can focus on the fundamentals of EBSD and EDS analysis as well as the specifics of each individual’s analytical goals without being bogged down or distracted by a clunky UI.

APEX Review mode is also quite popular with the user base. Our facility does charge user fees, so anything that makes someone’s instrument time more efficient without compromising the quality of their data is a big positive. We do quite a bit of EBSD and EDS mapping, and being able to process existing data or generate reports while new data is being collected simultaneously adds value to the time and money spent sitting and working at the FIB. Another simple yet valuable feature we appreciate is being given an estimated EDS map time before you start the map.

There has been positive feedback from users who conduct EBSD analyses regarding integrating EDAX OIM Analysis™ with the APEX software. Taking an APEX EBSD dataset and opening it in OIM Analysis to process the data is much more efficient than using the TEAM software. When it comes to EBSD, we want to ensure that we are operating the system carefully so as not to damage the camera. I prefer the separate software icons for EDS, EBSD, or Suite in APEX over the combined software of TEAM. This helps to ensure that a distracted user who is solely there for EDS doesn’t accidentally insert the EBSD camera – it happens.

All of this has made for a more streamlined approach to data collection, data analysis, and report generation on the FIB. The upgrade to APEX has allowed us to continue to produce quality data with improved efficiency in a high-throughput environment. It’s just something we didn’t realize we needed until we had it!

A fusion of excellence: the thrilling synergy of Gatan and EDAX in our merged company, advancing science in Central and Eastern Europe

Rudolf Krentik, Direct Sales and Distributor Manager CEE, Gatan/EDAX

In electron microscopy, precision and insight are the bedrock of scientific discovery. When Gatan, a company specializing in transmission electron microscopy (TEM), and EDAX, a leader in analytical scanning electron microscopy techniques, including energy dispersive x-ray spectroscopy (EDS), wavelength dispersive spectroscopy (WDS), and electron backscatter diffraction (EBSD) decided to merge, it created a unique and exciting environment. This is the story of how the merger of these two renowned companies changed the game, particularly how it transformed the landscape for scientists in Central and Eastern Europe (CEE), where I took a role as sales manager.

A symphony of expertise

Gatan brought its unparalleled knowledge of high-resolution TEM imaging, allowing scientists to scrutinize samples at the atomic level. On the other hand, EDAX excelled in SEM, capturing fine details while analyzing elemental composition. The merger was a meeting of minds and machines, combining the best of both worlds.

The power of integration

The fusion of Gatan and EDAX under one roof unleashed a wave of possibilities for scientists in CEE. Researchers, scientists, and engineers now have access to an unprecedented range of imaging and analytical capabilities. From exploring the innermost structure of nanomaterials with TEM to revealing the intricate topography of surfaces with SEM and conducting precise elemental analysis with EDS-WDS, the comprehensive suite of tools is a game-changer for those pushing the boundaries of science and technology in the region.

A new playground for discovery in CEE

The exciting environment that emerged from the merger has created a palpable synergy, which is especially beneficial to scientists in CEE. It’s not just about the advanced hardware but the convergence of ideas, collaboration, and innovation. Scientists in CEE are now working on projects that seamlessly transition between TEM, SEM, and EDS, gaining holistic insights that were previously unimaginable.

Whether it’s delving into the intricate lattice structures of advanced materials, meticulously examining the surface features of biological specimens, or identifying the elemental composition of a sample, the combined expertise and equipment offer the ideal platform for exploration. It’s no longer about choosing between TEM and SEM; it’s about having the best of both worlds for comprehensive analysis.

The impact on research and industry in CEE

The implications of this merger extend beyond the lab and profoundly affect research and industry in CEE. The seamless integration of TEM, SEM, and EDS accelerates research, product development, and quality control across various sectors.

One example is from the automotive industry. The fast-growing electronic vehicle market brought new challenges in analyzing lithium content in lithium batteries. Lithium is unstable when exposed to air and, hence, almost impossible to analyze in SEM. However, with the combination of a backscatter electron detector with very high dynamic range from Gatan and an EDAX EDS detector with extreme sensitivity for low energies, lithium can be mapped to see where it is and can be quantified with a high accuracy of 1 wt%.

Figure 1. (left) Map of the Li content in NMC 811 particles and (right) re-scaled Ni, Mn, Co, and O elemental maps after accounting for the Li content. Note that the grey color in the lithium map corresponds to regions of the sample that were not suitable for analysis by Cipher due to the significant fraction of H in the epoxy.

Providing cutting-edge technology in CEE

The merger has had a transformative impact on me, who is responsible for Central and Eastern Europe. It has allowed me to provide cutting-edge technology to scientists in the region, enabling them to make groundbreaking discoveries and advancements in their respective fields. The dynamic combination of our scientific products delivers the tools needed to push the boundaries of science in CEE.

Unveiling the power of EBSD in SEM

Furthermore, the EBSD technology provided by EDAX offers complete material characterization within the SEM. This addition has expanded the capabilities, providing scientists with a comprehensive solution for studying the microstructure and crystallography of materials. The latest development at EDAX provides the fastest EBSD cameras on the market and a solution for sensitive materials requiring low kV and low current conditions in SEM. All this is addressed by the first and only direct detection EBSD system, Clarity. Seeing the customer’s enthusiasm when you show them something that wasn’t possible until recently is great.

Figure 2. The EDAX Clarity EBSD Detector Series.

Enthusiastically looking to the future

Our entire European team is honored to be part of this incredible journey. We eagerly look forward to unforeseen developments in electron microscopy, materials analysis, and the world of science in Central and Eastern Europe. The possibilities are limitless, and as we continue to pioneer breakthroughs, the future looks even more thrilling. The journey has just begun, and the world of science and industry is the ultimate beneficiary of this exciting union.

Semper Fi

Matt Chipman, Sales Manager – Western U.S., Gatan/EDAX

Over the summer, I have been reflecting on the greater impact of my sales experience with EDAX and Gatan. The research our customers do tends to make life better for all of us collectively. I am proud to be a part of that, but often it’s difficult to see immediate impacts in the lives of people.

Some years ago, I was calling on a laboratory in Pearl Harbor, Hawaii, that does forensic anthropology in an attempt to account for missing service personnel from the US military. This was close to my heart because my father was missing in action before I was even two years old and was never accounted for. This lab didn’t end up purchasing my equipment, but it was well-equipped for the types of samples they would receive. They would use SEM-EDS to analyze aircraft crash site debris or anything that could be recovered that could prove the ultimate demise of U.S. soldiers. SEM-EDS plays an important role in forensic analysis by providing characteristics and compositional information of physical evidence (e.g., gunshot residue, glass and paint fragments, and explosives), which helps identify, compare, and correlate evidence to individuals, locations, or objects.

Figure 1. Captain Ralph Jim Chipman.

I didn’t know if any of the samples would end up being related to my father’s incident, but it was nice to know they had the tools needed and the motivation to keep searching. They indeed kept searching, and more than 50 years after the loss of his aircraft, they brought home a dog tag with my father’s name on it and a few teeth and bone fragments. The teeth positively identified my father. He is no longer missing! I am so grateful for those who never gave up looking.

Figure 2. Notice saying Captain Ralph Jim Chipman is no longer missing in action.

I am hopeful that material from the crash site still being analyzed can positively identify the navigator who sat next to my father in the aircraft. I also hope to learn whether electron microscopy and x-ray spectroscopy was an instrumental part of this effort to sift through different kinds of evidence. I am glad to have associated with some of the many people who keep searching. This work makes lives better and can have a huge impact on individuals and families of those lost. I am honored to be a small part of research that makes all of our lives better and can have a huge impact on people we will likely never meet.

Semper Fi!

Embracing the return

Dr. Shangshang Mu, Application Scientist, Gatan/EDAX

Over the past year, I’ve rekindled my enjoyment of traveling as I visited customers in the Americas, Asia, and across Europe. During my return journey, I was deeply touched by an airline billboard at the Munich, Germany airport that read, “We all live under one sun. Let’s see it again.” Indeed, it is genuinely nice to see the world once more since reemerging from the pandemic.

While flying over Hudson Bay, an inland marginal sea of the Arctic Ocean, I saw numerous ice caps floating on the water from the aircraft’s belly camera view. To me, these were very reminiscent of the counts per second (CPS) map (Figure 1) in one of the wavelength dispersive spectrometry (WDS) datasets I shared with customers during these trips. Although they were orders of magnitude larger than the micron-scale sample, the resemblance was striking.

Figure 1. Ice caps in Hudson Bay (left) resemble the CPS map of a Si-W-Ta sample (right).

Throughout these journeys, our EDAX Lambda WDS system was one of the hot topics drawing customers’ attention. This parallel beam spectrometer features a compact design compatible with almost every scanning electron microscope (SEM). The improved energy resolution and sensitivity and lower limits of detection make it an excellent supplement to your energy dispersive spectroscopy (EDS) detectors. The CPS map I referred to was captured from a Si-W-Ta sample. The energy peaks of Si K, W M, and Ta M are heavily overlapped, with only approximately 30 eV energy difference between each other. Lambda WDS systems provide up to 15x better energy resolution than typical EDS systems, effectively resolving the ambiguity in analysis.

Figure 2. Overlay of EDS (red outline) and WDS (cyan color) spectra from the central area of the Si-W-Ta sample.

The overlay of EDS/WDS spectra from the central area of the map shows that the Lambda WDS system intrinsically resolves the overlapping EDS peaks (red outline), as depicted by the cyan color WDS spectrum (Figure 2). The shortcoming of EDS in resolving these overlapping peaks results in the distributions of the three elements appearing identical in EDS maps. However, the WDS maps provide clear and distinct visualizations of the individual distributions of the three elements (Figure 3).

Figure 3. EDS (top) and WDS (bottom) maps of the Si-W-Ta sample. The WDS maps resolve the artifacts due to Ta M, Si K, and W M peak overlaps in the EDS maps.

This year’s M&M meeting is just around the corner. If you are traveling to this entirely in-person event, stop by our booth (#504) to check out our integrated EDS-WDS SEM solutions and many other products that will capture your interest.

APEX, now with WDS!

Dr. Shangshang Mu, Applications Engineer, Gatan/EDAX

The new APEX™ 3.0 is the ultimate materials characterization software, integrating Energy Dispersive Spectroscopy (EDS), Electron Backscatter Diffraction (EBSD), and Wavelength Dispersive Spectrometry (WDS) to deliver previously unattainable solutions. This optimized configuration offers the uncompromised performance of each technique and allows users to combine them for the ultimate materials insight. All three techniques seamlessly operate within the APEX, blending powerful elemental and crystallographic analysis routines through an intuitive interface to deliver outstanding data collection, faster analysis, and flexible reporting for users of all levels.

What does APEX WDS look like?

WDS functionalities are implemented seamlessly with the EDS graphical user interface. The user can quickly adapt to the new functionalities and employ WDS when and where EDS reaches the limit. With one-click from start to finish, Auto WDS allows fully automated WDS scan list generation, optimum sample height determination, and spectrum collection. It simultaneously collects EDS and WDS spectra and displays them side-by-side or overlaid for easy data visualization and interpretation (Figure 1), with no overlapping or overloading of windows.

Figure 1. Simultaneous EDS-WDS spectrum acquisition user interface.

APEX allows you to set an intermediate position for the EDS detector to ensure optimal count rates for both techniques.

Figure 2. Simultaneous EDS-WDS mapping user interface.

Sets of combined EDS-WDS spectrum, linescan, and mapping data at different stage positions can be done via automated batch collection routines (Figure 2) to streamline SEM experiments. EDS and WDS data collection settings are managed in one user-friendly batch scan list (Figure 3).

Figure 3. Combined EDS-WDS batch list.

The quantitative elemental analysis supports individual technique or combined EDS-WDS standards. You can easily switch between EDS and WDS standards for each element by clicking on the icon in front of the element (Figure 4).

Figure 4. Quantitative results with combined EDS-WDS standards.

With the addition of WDS capabilities, APEX 3.0 now includes EDS, EBSD, and WDS. Each characterization tool can operate independently to utilize EDAX’s technological advancements or integrates data to provide solutions that were once unachievable.

Is lack of invention a side effect of COVID?

Dr. David Stowe, Senior Product Manager – EDS and SEM Products, EDAX/Gatan

My friends and family have always thought that, as a microscopist, I spend my working days in a darkened room staring at dimly lit screens or developing negatives. Yet, the reality of working for a commercial company in the electron microscopy business could hardly be more different—scientific meetings, workshops, and spending time with users have allowed me to travel the world and make friends with some of the most interesting people. It’s always been a source of wonder and amazement for my family that the microscopic world could provide so many opportunities to see our world at large!

Sadly, over the last two years, our daily routines have been aligned much more closely to those visions of darkened rooms and computer screens than we care to remember. However, for many of us, there does appear to be (sun)light at the end of the tunnel. In recent weeks, I attended my first in-person workshop in almost two years. Together with colleagues and more than 60 researchers, I traveled to Munich to attend the Gatan-EDAX Leading Edge Workshop held at the Allianz Arena (home to Fußball-Club Bayern München e. V.—known to many as Bayern Munich). As lovely as it was to visit such a famous sporting stadium, the enjoyment of attending scientific talks and engaging in exciting technical discussions with leading researchers far outweighed the attraction of the venue. The feedback from everyone who participated in the day was incredibly positive. Many of us walked away from the event with new ideas inspired by discussions that day.

One of my fears regarding the impact of COVID-19 on the scientific community is the impact that the lack of these in-person interactions has had on innovation, both in terms of new scientific ideas and technological advancements. While working from home, many of us have missed those stimulating ‘coffee break conversations’ with colleagues outside of our teams. To add, there has been a noticeable drop in interactions on virtual platforms at scientific conferences and commercial webinars, with many preferring to review material offline at a time of their choosing.

Fortunately for EDAX, the opportunity for engagement with others during the pandemic had rarely been as high. Since 2019, we have been joined in the Materials Analysis Division of AMETEK by Gatan; the exchange of ideas between the R&D and Applications teams of the two companies has been significant. Within the last year, we have already seen the first innovations arising from the interactions between the two companies with the announcement of EDAX EDS Powered by Gatan for elemental analysis in the transmission electron microscope, simultaneous EDS and cathodoluminescence spectroscopy, and the development of a workflow solution for lithium analysis in the scanning electron microscope.

Within the last month, our applications teams were able to quantify the lithium content in lithium-ion battery cathode materials for the first time using the lithium-composition by difference method (Li-CDM).

Figure 1. First quantitative analysis of lithium content in cathode materials using the Li-CDM technique.

Their analysis used a range of tools from EDAX and Gatan to prepare, transfer, and analyze the specimen in the scanning electron microscope, highlighting the potential for innovation by Gatan and EDAX working together.

Figure 2. The tools from EDAX and Gatan used for the quantitative analysis of lithium in metal oxide cathode materials.

With the imminent arrival of the latest Microscopy and Microanalysis conference in Portland, OR, I am sure we will learn far more about how the changes to working practices have impacted innovation in our world. I am excited to leave my darkened room and discover your latest works in electron microscopy. I am sure that all participants will enjoy and value the personal interactions that are so important for innovation.

Inflation Got You Down?  

Matt Chipman, Sales Manager – Western U.S., EDAX and Gatan

I recently watched a local news story about inflation in consumer goods. The reporter wanted to know if the dollar store could save you money on groceries. The general answer was perhaps on some items, but it wasn’t significant. However, it was interesting to see how some stores focus on a perceived value instead of a real value to its consumer. First, the dollar store raised its starting price from $1.00 to $1.25. Then they used odd-sized packages that were not equivalent to regular grocery store items, making a direct comparison difficult and offering minimal to no real savings. Finally, the dollar store’s selection was very limited so you may end up back at the regular grocery store for anything other than packaged goods.

So, what does this have to do with the microanalysis business? Well, I believe it’s important to look at the big picture with real, tangible benefits that can impact your research. By offering both EDAX and Gatan products, there are more opportunities to combine different technologies to enable unique analyses that can provide a tremendous value to your material studies.

One great example is the quantification of lithium on a scanning electron microscope. By uniting Gatan’s low-kV OnPoint™ Backscattered Electron Detector with EDAX’s Octane Elite Super EDS Detector, this one-of-a-kind analysis is now possible, surpassing what can be done by either technique alone.

Figure 1. The lithium mapping from joint characterization of the EDAX Octane Elite EDS Detector and Gatan OnPoint BSE Detector.

Not to forget, we’ve also been combining the strengths of the Gatan DigitalMicrograph® Software with the EDAX EDS detector technology for TEMs. I believe we are just beginning to scratch the surface of creative things we can do by joining microanalysis systems and techniques. I love discussing creative ways my customers can coalesce microanalysis techniques to do something new.

Figure 2. Multimodal data acquisition of EELS and EDS data combines the chemical sensitivity of EELS with the broad compositional mapping of EDS. Pictured – STEM EELS/EDS mapping of vertical channel 3D NAND acquired with DigitalMicrograph software.

I hope we can all figure out ways to get a real, noticeable value from the equipment we purchase during this time of inflation. I hope to hear ideas from some of you as you tell me about the needs of your laboratories.

EDAX and Gatan Bring You Lithium

Dave Durham, Sales Manager – U.S. Western, EDAX

It has been interesting to recently witness EDAX and Gatan working together to combine the technologies in our portfolios. Although technically, Gatan was acquired by AMETEK back in late 2019, it seems like 2021 has been a year where the integration of our two companies has really begun to hit its stride.

For example, I’ve seen how Gatan’s ion polishing instruments can dramatically improve indexing success for EDAX’s Electron Backscatter Diffraction (EBSD) users compared to the conventional methods for sample preparation. And I’ve seen EDAX’s Elite T Energy Dispersive Spectroscopy (EDS) System undergo a tremendous workflow improvement and ease-of-use overhaul with the implementation of Gatan’s Microscopy Suite user interface. It has been great stuff!

However, the most recent integration between our two companies is truly groundbreaking, and I’m thrilled to see what it will do to enhance the research being done in its field.

Hopefully, you’ve already seen the news mentioned on our website. For the first time, we’ve been able to perform quantitative mapping of lithium in the Scanning Electron Microscope (SEM) by combining the power of EDAX and Gatan detectors and software! These breakthrough results will enable a new level of lithium research that was previously never possible with the SEM.

Figure 1. EDAX and Gatan bring you lithium.

So who cares about lithium? Everyone should. Lithium compounds and alloys are very important materials with significant commercial value. The compounds are being implemented into lightweight structural alloys in the aerospace and automotive industries. They’re also utilized in lithium-ion batteries for small electronic devices and vehicles. Many governments worldwide have proposed plans to reduce dependence on legacy energy sources, which makes further development of lithium-based technologies critical to the adoption of these plans. This means significant investments are currently being made in R&D, failure analysis, and quality control of these materials.

Figure 2. (left) Lithium-ion battery cross-section prepared by Ilion II broad beam argon milling system. (right) EBSD IQ + orientation map revealing the microstructure of the heat-affected zone in a lightweight structural alloy.

So what are the issues with lithium? While electron microscopy and EDS are already essential characterization tools in this industry, there is a distinct inability to map lithium distribution in the SEM. This has presented a significant obstacle, holding back research on these tools. EDS is typically a valuable technique for material characterization, with high sensitivity and spatial resolution to allow for quantitative analysis on a wide range of sample types. But it is not possible to identify lithium in commercially important materials by EDS because:

  1. There is no guarantee that lithium X-rays will be produced from the sample. The X-ray energy and the number of photons produced from the specimen depend on the lithium bonding state. So, even if you have lithium in your sample, it does not mean that lithium X-rays will be generated.
  2. Even if a sample does generate lithium X-rays, they are easily absorbed back into the sample itself, contamination or oxidation, or by the EDS detector window before they can even reach the EDS detector.

Indeed, specialized windowless EDS detectors can detect lithium, but these have drawbacks that impede their practicality and largescale adoption. Even on samples that have a high lithium fluorescence, these special detectors have a limit of detection of about 20 wt %. This is equivalent to about half of the atoms in the sample being lithium, which restricts analysis to only metallic lithium or simple lithium compounds that may not be relevant to advanced lithium research or applications.

And having a specialized windowless EDS system potentially introduces a slew of operational issues/limitations with the detector that aren’t present with a “standard” windowed EDS system. It also restricts the detector’s utility on non- lithium -research-based applications in the lab.

So what have EDAX and Gatan done? We have solved these issues by using a patent-pending technique called the Composition by Difference Method. In this method, we quantify the backscattered electron signal to determine the mean atomic mass for all elements in a particular area of a sample. And from the same region, we collect the EDS signal to quantify the non-lithium elements. From that information, we have two data points that tell us the actual mean atomic mass from the region and a calculated value based on the EDS results — when they don’t agree with one another, it tells us we are missing something in the EDS data. That something we’re missing is lithium.

Figure 3. Data from the OnPoint and the Octane Elite Super are combined and analyzed to quantify lithium.

By using this method, and specifically by combining the EDAX Octane Elite Super EDS Detector and the Gatan OnPoint Backscattered Electron Detector to collect these two signals, we can now generate lithium maps quantitatively with single-digit mass percentages of lithium with sub-micron spatial resolution. This accuracy has been verified to ~1 wt. % lithium by an external accredited laboratory using Glow-discharge Optical Emission Spectroscopy (GDOES).

Figure 4. Secondary electron image and elemental metal fraction maps (by wt. %) of the same region of the MgLiAl alloy; white pixels are regions excluded from the analysis due to the influence of topography (identified by arrows in the secondary electron image) shown here for clarity.

This is a cutting-edge capability in the SEM, and it is a huge opportunity for anyone wanting to discover where lithium exists in their specimens. Just to reiterate, this method does not use a specially designed EDS system for lithium detection! It uses EDAX’s standard (windowed) Octane Elite Super and Gatan’s OnPoint BSE detector, along with EDAX and Gatan software. Simply amazing!

Now that EDAX and Gatan have introduced the ability to provide quantitative lithium analysis, that is:

  • A substantial improvement in limits of lithium detection
  • Insensitive to the lithium bonding state
  • More tolerant to contamination and oxidation
  • Not limited to metallic materials or simple lithium compounds
  • Free from windowless detector-related limitations on the SEM

It seems that we have helped open an avenue for our customers to expand their lithium research beyond anything previously possible. We are truly beginning a very exciting new stage in lithium analysis, and I can’t wait to see how this new capability is used and what comes next!

You can find more information on this new development in our experiment brief.

Research Must Go On

Rudolf Krentik, Sales Manager – Central and Eastern Europe, EDAX

It has been some time since I started working at EDAX as an Area Sales Manager for Central and Eastern Europe. When I think about it, Russia is by far the largest region compared to all the others. If sales grew linearly with the size of the area, I would probably be a millionaire. Unfortunately, it is not the case. The primary purpose of my work is to take care of our distributors and business partners in individual countries. I give them support in business cases, provide up-to-date information about our products, and sometimes I am also an intermediary for the serious requirements of our end customers. The work is very interesting, especially because I meet interesting people. EDAX’s customers are primarily scientists and engineers studying materials, solving complex problems, and dealing with development and innovation. Such meetings are often very fun, inspiring, and rewarding.

Figure 1. My new office.

The market situation has changed dramatically since 2015, when I started. COVID-19 has completely changed the way we work. Instead of meeting customers at scientific conferences, we all locked ourselves in our homes for a long time. After three months, I couldn’t stand it and rented a small office so that I wouldn’t go crazy at my home office with my wife and two small children, who were also schooling and working from home. So I was moving from my home office to an actual office, doing just the opposite of what others were doing during the pandemic.

Moving from real life to the online world was probably frustrating for many of us. Still, we had to adapt and start selling and communicating over the phone and especially over the internet. Online presentations and meetings are still the order of the day. This way of communication will be maintained in the future, that is quite certain. Unfortunately, this does not replace personal contact, which is essential for creating a relationship with customers. It can already be seen that interest in virtual conferences is declining. People are inherently interactive and need to share their needs and feelings with each other. This is not possible in the world of the internet. Therefore, we all hope that everything will return to normal soon. Our service technicians have been traveling to places where it is safe for quite a long time, and we salespeople are also starting to plan our first trips abroad. I’m actually partly writing this blog in Turkey on my first trip in 18 months.

Although it does not seem so, COVID has not yet caused significant losses or loss of orders in terms of business results. Our business is still in good condition. One of the factors that affects this is the life cycle of a business case. This can take months or even years. If we do not soon return to the life we are used to; it will have very negative consequences for our field. I mention this because we are currently at the stage where we want to launch several exciting products. You probably know that Gatan also belongs to our AMETEK family. The company is known for its leading technology in detection systems in TEM and SEM and other devices, e.g., for sample preparation. The acquisition of Gatan is a great benefit not only for AMETEK but also for EDAX. The combination of know-how, development, and experience in the electron microscopy field creates space for innovation and synergies that would not be possible.

Several novelties were introduced three weeks ago at M&M 2021. It is worth mentioning the EDAX EDS Powered by Gatan, in which EDAX hardware is now integrated into the software from Gatan. This brings many benefits, such as a unified GUI for all the TEM techniques available from Gatan. EDS analysis with Elite T can now be performed seamlessly with Gatan EELS, 4D STEM (STEMx), or other techniques. This makes it all much easier and faster. And as we know, time is money, and this is doubly true for time spent at the TEM.

Another interesting novelty is the cooperation of EDS and CL detectors. Thanks to an EDS-compatible cathodoluminescence (CL) mirror that enables line of sight from the sample to the EDS detector while still collecting the CL signal, we can obtain information about the material’s structure that was previously difficult to achieve.

When it comes to EBSD, EDAX has been the leading provider of this technique since the 90s. But for reliable analysis, one needs a high-quality sample preparation tool. Again, with the Gatan PECS II, we can offer a complete workflow from getting the sample ready to post-processing of acquired data. The latest news is also the hottest news. With the help of the highly sensitive OnPoint BSE and Octane Elite EDS Detectors, it is possible to detect lithium for the first time and quantify it. Unique technology, the accuracy of which is verified by another method, is now available and we are very anxious to introduce this product to our customers.

That is why we need to get the COVID-19 pandemic under control. Without the opportunity to travel and meet our customers, our work will be inefficient and not as much fun. However, the newly introduced devices and the ongoing development of the EDAX-Gatan collaboration gives us a strong hope that everything is on track and that our efforts are worthwhile.