EDAX

Do not try this at home: Microwave-Rubies

M. Sc. Julia Mausz, Application Scientist, Gatan/EDAX

Synthetic gemstone quality rubies are commonly manufactured with the Verneuil process, which got its name from its ”father ” Dr. A.V.L. Verneuil. This process was designed to produce single crystalline synthetic rubies and can now be used to melt a variety of high melting point oxides. The details of this flame fusion process were already published in 1902-1904 [1]. As I have neither a ruby mine nor a flame fusion device handy, I aimed to manufacture rubies using a different approach. However, I was unsure if it was possible to form single crystals or even large grains with this technique.

Like in the Verneuil process, the starting point of my synthetic rubies was Al2O3 and Cr2O3 powder. Those were homogeneously mixed, aiming at 1 – 2 at. % chromium content. Considering the melting point of Al2O3 (2,038 °C) [2] and Cr2O3(2,435 °C) [3], the maximum local temperature required to melt a powder mixture of both is 2,435 °C.

A microwave-induced plasma will supply the heat. With an operational frequency of about 2.450 GHz, kitchen microwaves can create high temperature plasmas, even at atmospheric pressure [4]. While bulk metals undergo little heating from microwaves due to the reflection of the waves, it is possible to heat fine-grained metal particles with dielectric heating. However, there is a more effective phenomenon to heat metal with microwaves. Electric discharge can occur due to changes in the distribution of charges when a conductive material with a sharp edge or tip is exposed to microwaves in that frequency regime. The heat resulting from the discharge dissipates very locally into the conductive material, resulting in temperature hot spots able to melt metals and metal oxides in direct contact with the metal, as shown later [5] [6] [7].

The main gases relevant for the plasma will be nitrogen (approx. 78%) and oxygen (approx. 21%) from the surrounding air. The electron source to ignite the plasma will be fine, sharp aluminum edges. Therefore, the powder mixture was placed in a glass crucible and covered with a network of fine aluminum stripes. The crucible was shallow and closed with a glass lid to prevent the hot gas from rising away from the powder. Then, the microwave was operated at 900 W and could sustain the plasma for 60 s. Then, the fused parts were collected from the powder, cleaned, and mounted onto an aluminum stub for observation in the SEM. The resulting fused particles were in the order of 0.5 – 2 mm and already showed the expected pink to purple color, which can be seen in Figures 1a and 1b. The fluorescence yield of rubies can be seen under black light. Without blacklights available, I needed to rely on the 8 kV argon ion beam from the Gatan PECS™ II, and the resulting fluorescence is shown in Figure 1c.

a) Various rubies mounted on a carbon tape. b) Detailed view of the rubies under an optical microscope. c) Fluorescing ruby in an argon ion beam in the PECS II using stationary single beam from one side.

Figure 1. a) Various rubies mounted on a carbon tape. b) Detailed view of the rubies under an optical microscope. c) Fluorescing ruby in an argon ion beam in the PECS II using stationary single beam from one side.

The Zeiss Sigma 500 VP SEM was set to 12 kV acceleration voltage, 120 μm aperture, and 3 Pa low vacuum to prevent charging. The microstructure was then analyzed on the unpolished surface using the EDAX Velocity Super EBSD detector. After fusion of the powder, the resulting ruby has a smooth surface with the crystal structure extending all the way to the surface. Therefore, the ruby could be indexed without any polishing step. It is fascinating with how much ease and speed an unpolished, charging material could be analyzed.

Hough indexing already achieved high indexing rates, considering the dirt and the shadowing on the sample. To bring back even more shadowed points and to refine the grain boundaries, I reprocessed the dataset using Neighbor Pattern Averaging & Reindexing (NPAR™) [8] and spherical indexing [9]. For spherical indexing, a dynamic simulation of trigonal Al2O3 was used. For each, the image quality (IQ) map [10] and confidence index (CI) map, an overlay of the orientation map is shown in Figure 2.

Figure 2. Ruby surface. a) IQ map, b) IQ map + IPF map with CI > 0.2 filter and CIS, c) CI map, and d) CI map + IPF map with CI >0.2 and CIS.

The dataset clearly shows a polycrystalline structure. Note that although the grains can be easily recognized, the shape and size of the grains are distorted due to the variation in surface topography.

In contrast to the grain shape, misorientation and texture analyses are unaffected. The detected bands in the EBSD patterns are direct projections of the lattice planes. As the active lattice planes are independent of the surface structure, the measured crystal orientation is not affected by the surface orientation.

The orientation map is displayed in Figure 3a after applying the confidence index standardization (CIS) procedure and a CI filter of 0.2. Figure 3b shows the overlay of this orientation map with its corresponding CI map and the grain boundaries with a minimum misorientation angle of 5° marked in black.

Figure 3. Ruby surface. a) IPF map with CI >0.2 and CIS and b) overlay of IPF map with CI >0.2 and CIS with grain boundary (>5°) in black and CI Map after CIS.

Interestingly, the as-fused state of the ruby showed a clear spike in the misorientation angle of 60°, as shown in Figure 4a. The twin boundaries of 60° with a tolerance angle of 2° are marked in black on top of the detail orientation map in Figure 4b. The crystal wire figure is schematically shown on both sides of the twin boundary, showing a 60° rotation along the c-axis.

Figure 4. Ruby surface. a) Misorientation chart with black highlighting and b) orientation map with black twin boundaries and crystal visualization of both sides.

In Figure 5, the (0001) texture pole figure reveals a weak texture. The orientation maximum is shifted somewhat towards the top-right, corresponding to the surface’s slanting in the same direction. This suggests that there is a weak preferred orientation of the (0001) planes parallel to the surface of the ruby aggregate particle.

Figure 5. Ruby surface. Texture Pole Figure.

It is possible to form synthetic rubies using microwave-induced plasma in a commercial microwave oven. However, the resulting rubies are small, of unpredictable shape, and due to their polycrystalline nature, not of high clarity. While ruby production in the microwave did not qualify to open a gemstone side business, it is a reliable source for making interesting EBSD samples, and we might see some more gemstone blogs in the future.

References

  1. NASSAU, K. Dr. AVL Verneuil: The man and the method. Journal of Crystal Growth, 1972, 13. Jg., S. 12-18.
  2. SCHNEIDER, Samuel J.; MCDANIEL, C. L. Effect of environment upon the melting point of Al2O3. Journal of Research of the National Bureau of Standards. Section A, Physics and Chemistry, 1967, 71. Jg., Nr. 4, S. 317.
  3. GIBOT, Pierre; VIDAL, Loïc. Original synthesis of chromium (III) oxide nanoparticles. Journal of the European Ceramic Society, 2010, 30. Jg., Nr. 4, S. 911-915.
  4. KOCH, Helmut; WINTER, Michael; BEYER, Julian. Optical Diagnostics on Equilibrium and Non-equilibrium Low Power Plasmas. In: 48th AIAA Plasmadynamics and Lasers Conference. 2017. S. 4158.
  5. SUN, Jing, et al. Review on microwave–metal discharges and their applications in energy and industrial processes. Applied Energy, 2016, 175. Jg., S. 141-157.
  6. LIU, Wensheng; MA, Yunzhu; ZHANG, Jiajia. Properties and microstructural evolution of W-Ni-Fe alloy via microwave sintering. International Journal of Refractory Metals and Hard Materials, 2012, 35. Jg., S. 138-142.
  7. ZHOU, Chengshang, et al. Effect of heating rate on the microwave sintered W–Ni–Fe heavy alloys. Journal of Alloys and Compounds, 2009, 482. Jg., Nr. 1-2, S. L6-L8.
  8. WRIGHT, Stuart I., et al. Improved EBSD Map Fidelity through Re-indexing of Neighbor Averaged Patterns. Microscopy and Microanalysis, 2015, 21. Jg., Nr. S3, S. 2373-2374.
  9. LENTHE, W. C., et al. Spherical indexing of overlap EBSD patterns for orientation-related phases–Application to titanium. Acta Materialia, 2020, 188. Jg., S. 579-590.
  10. WRIGHT, Stuart I.; NOWELL, Matthew M. EBSD image quality mapping. Microscopy and Microanalysis, 2006, 12. Jg., Nr. 1, S. 72-84.

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!

It runs (or rolls) in the family

Matt Nowell, EBSD Product Manager, Gatan/EDAX

I have two sons graduating this year. My oldest son is graduating college with a Materials Science and Engineering degree and is interested in materials characterization. My middle son is graduating high school and has grown up refining ores in Minecraft, casting characters from Dungeons and Dragons, and 3D printing school projects. I’m glad they are both interested in materials and how they can affect daily living. I’ve also been a little sentimental and nostalgic thinking about how we have tried to learn more about materials in our household.

One activity they have always enjoyed is collecting pressed coins. These machines squeeze a coin between two rollers, one of which has an engraving on its surface that is then imprinted onto the stretched and flattened surface of the deformed coin. We have collected these coins from around the world. One example is shown in Figure 1, which is a pressed coin from Universal Studios. This was the most recent addition to the collection. I decided to press a second coin that we could prepare and characterize with electron backscatter diffraction (EBSD) to see the microstructural developments that occur during the pressing process.

Figure 1. A pressed coin from Universal Studios.

The pressed coin was mechanically polished down to 0.02 µm colloidal silica and then analyzed using the new EDAX Velocity Ultra EBSD detector. This new detector allowed for high-speed data collection at acquisition rates of 6,500 indexed patterns per second. Figure 2 shows the inverse pole figure (IPF) orientation map collected from a 134 µm x 104 µm area with a 100 nm step size, with the coloring relative to the orientations aligned with the sample’s surface normal direction. At these speeds, the acquisition time was less than five minutes. A copper blank was used instead of the traditional penny for this sample. This was noticeable when indexing the EBSD patterns. Since 1982, pennies have been made of zinc coated with copper. Zinc has a hexagonal crystal structure, while the EBSD patterns from this coin were face-centered cubic (FCC). EDS analysis confirmed that the material was copper.

Figure 2. An IPF orientation map collect from a 134 µm x 104 µm area of the pressed coin with a 100 nm step size. The coloring is relative to the orientations aligned with the sample’s surface normal direction.

The IPF map shows a significant amount of deformation. This can be seen in the IPF maps with the color variation within each grain. This is, of course, expected, as the elongation and thinning of the coin are easily observed while watching the machine. EBSD is an ideal tool for characterizing this deformation within the material. While there are several different map types to visualize local misorientations and deformation, Figure 3 shows one of my favorites, the grain reference orientation deviation (GROD) map. In this map, the grains are first calculated by grouping measurements of similar orientation using a 5° tolerance angle. Next, the average orientation of each grain is calculated. Finally, each pixel within a grain is colored according to its misorientation from the average orientation of its grain. The microstructure’s largest GROD angular value is 61.9°, indicating a large spread of orientations. This map also shows the grain boundaries as black lines to indicate the original grain boundary positions.

Figure 3. A GROD map of the pressed coin.

Figure 4 shows a fascinating view of how the material is deformed within a selected grain. This chart was created by drawing a line within a grain and plotting the point-to-point and point-to-origin misorientations along this line. The point-to-point distribution shows that each step is typically a small misorientation value below the grain tolerance angle. The point-to-origin distribution shows an accumulation of misorientations within this grain, with the overall misorientation changing more than 30° over the 25 µm distance within the grain. This type of result always gets me thinking about what a grain really is in a deformed material.

Figure 4. A view of how the material is deformed within a selected grain. This chart was created by drawing a line within a grain and plotting the point-to-point and point-to-origin misorientations along this line.

Figure 5. The (001), (111), and (110) pole figures calculated from the measured orientations.

Figure 5 shows the (001), (111), and (110) pole figures calculated from the measured orientations. These pole figures are incomplete and resemble what is expected for a rolled FCC material. This is due to the small number of grains sampled in this area. A second map was collected over a 1,148 µm x 895 µm area with a 2 µm step size in under a minute to get a better sampling of the entire microstructure. The pole figures for this data are shown in Figure 6. Comparing Figures 5 and 6 shows that the additional sampling within the second scan adds more symmetry to the pole figures.

Figure 6. The pole figures for the second map that was collected over a 1,148 µm x 895 µm area with a 2 µm step size.

This was a fun example to show the different data types that can be derived from EBSD measurements. In materials science, understanding the relationship between materials processing and the resulting microstructure is critical to understanding the material’s final properties. It’s clear that pressing a coin causes significant deformation within the material, which can then be measured and quantified with EBSD. Maybe the next time we go to the zoo, we will vary the speed at which we roll the coins and see what effect that has on the data.

A Cog’s Case for Corporate Utopia

David Durham, Regional Sales Manager, EDAX

Not too long ago I went to my optometrist to get an eye exam for some replacement glasses. My last pair had been stolen after my car was broken into in broad daylight during lunch at a restaurant in the Bay Area. (What the thief planned on doing with my prescription glasses is still a mystery to me.)

Figure 1: The old phoropter* (top) and the new phoropter** (bottom).

It had been at least a couple years since my last examination, but I was prepared to be guided through all the typical tests, culminating with that “giant-machine-with-multiple-lenses” pressed into my face to help the optometrist determine the prescription that would best correct the errors in my vision. I’d later learn that this machine is called a phoro-optometer, or more commonly a “phoropter.” And, contrary to my previous experiences with this instrument, it was now a super-sleek, slimmed down, digital version of the machine, using a computer controlled digital refraction system to cycle through the refraction options instead of using stacks of physical lenses that had to be manually cycled by the optometrist.

It was much smaller, quieter, faster, and easier than the version with which I was familiar. I was thoroughly impressed. But I was even more impressed when the instrument was pulled away and I saw the Ametek logo emblazoned on the side of it.

I couldn’t help but reflexively blurt out “Hey I work there!” to which the optometrist looked up from my file and began curiously interrogating me about my history in the eye care industry. Sadly, he quickly lost interest after I explained that I worked in a different division of Ametek that manufactures EDS, EBSD, and WDS systems.

After my exam, for some reason I felt a bit intimidated about not knowing more about Ametek’s business units outside of the EDAX niche to which I belong. I knew Ametek was a huge corporation, steadily growing larger over the decades — mainly by acquisition of smaller companies – but I’d never really grasped the sheer size and breadth of everything Ametek does. This wasn’t the first time I’ve been in this type of situation. Prior to joining EDAX/Ametek I worked for another scientific instrumentation corporation, slightly smaller than Ametek but still a similar type of behemoth with a wide range of companies making products that service comparable industries and applications. Even at that corporation my knowledge of the business outside of my business unit’s portfolio was very limited. These places are just so big!

Working at large corporations like these can, at times, be a little bit discouraging if you think of yourself as just a single cog in a machine with thousands of moving parts. Giant corporations certainly seem to have a bad reputation these days and I’ll admit I’ve experienced my fair share of corporation-induced angst over the years. Working within a large bureaucracy can make completing the smallest internal tasks overwhelming. Being in a smaller company that is acquired – I’ve been through two acquisitions — can be disruptive to business and cause a lot of anxiety.

But is there a good side to these mega-corporations? I think so.

I can find some important benefits that could be argued to outweigh the negative aspects, not just to the cogs like myself but also to the markets that they serve. Whether or not these apply to other more prominent mega-corporations is debatable, but I think they seem to be reasonable positive characteristics, at least from my experience in the scientific instrumentation field.

Having the brand name recognition has always been an advantage. Customers (and their procurement departments) are typically more willing to do business with companies that have a long history of manufacturing products. Being in business for multiple decades with a proven track record of having the resources to reliably deliver products to the market and consistently service its user-base generates heaps of reassurance for customers that a younger or smaller company just can’t provide. It works similarly for vendors as well – it turns out that people are always more willing to sell you stuff if they’re confident that your company will pay for it.

Being in a large corporation also offers a huge advantage in the ability to research and develop new technology and product improvements. This can come by brute force – having deeper pockets to invest more money into R&D – or even by utilizing the synergy between individual companies under the corporation’s umbrella. EDAX is a great example of this in a couple ways. Ametek’s purchase of a new business unit in 2014 facilitated the development of EDAX’s groundbreaking Octane Elite and Octane Elect EDS systems, allowing for speed and sensitivity that had never been achieved before in any other EDS system. Collaboration between EDAX and another sister company within the Materials Analysis Division of Ametek, ushered in the release of EDAX’s new Velocity™ highspeed CMOS EBSD camera, by far the fastest EBSD system available. Realization of these two milestones of innovation would have been significantly delayed without the help of Ametek’s resources.

Figure 2: The Octane Elite (left) and the Velocity™ Super (right), two of EDAX’s products that were developed, in part, with the help of other business units inside Ametek.

But what I think tends to be the best part is that, as long as a company is meeting its targets and things are humming along nicely, corporations – at least the good ones, in my opinion — are usually happy to just let the business unit do its own thing. Having an “if it ain’t broke don’t fix it” mentality is the ideal way to keep the key talent happy and keep the business growing and making money. It also makes it possible to retain some semblance of the original company culture that contributed to its success in the first place. This is the holy grail for us cogs – being able to keep that small business feel while also being able to take advantage of all the big business benefits at the same time. Again, EDAX is a good example of this, with many of EDAX’s employees being legacy staff hired on long before the EDAX acquisition. This tells me Ametek must be doing something right.

So, I guess it’s debatable. While we may be willingly marching our grandchildren into a dystopia where three or four companies own all the businesses in the world, there are some undeniable advantages that working for a big company brings as well. And I take some comfort in the fact there are some very intelligent and innovative people behind the curtains, trying to do good things to make their customers happy and generally improve the lives of everyone in the world. We may or may not see all the things like the better phoropters out there, but our lives are almost certainly benefited by them whether we realize it or not.

* Photo from https://en.wikipedia.org/wiki/Phoropter
** Photo from http://www.reichert.com/

Saying What You Mean and Meaning What You Say!

Shawn Wallace, Applications Engineer, EDAX

A recent conversation on a list serv discussed sloppiness in the use of words and how it can cause confusion. This made me consider that in the world of microanalysis, we are not immune. We are probably sloppiest with two particular words. They are resolution and phase.

Let us start with how we use the word phase and how phases are commonly defined in microanalysis. In Energy Dispersive Spectroscopy (EDS), we use phase for everything, for example, phase mapping, phase library. In Electron Backscatter Diffraction (EBSD), the usage is a little more straightforward.

So, what is a phase? Well to me, a geologist, a phase has both a distinct chemistry and a distinct crystal structure. Why does this matter to a geologist? Two different minerals with the same chemistry, but with different structures, can behave in very different ways and this gives me useful information about each of them.
The classic example for geologists is the Al2SIO5 system (figure 1). It has three members, Kyanite, Sillimanite, and Andalusite. They each have the same chemistry but different structures. The structure of each is controlled by the pressure and temperature at which the mineral equilibrated. Simple chemistry tells me nothing. I need the structure to tease out that information.

Figure 1. Phase Diagram of the Al2SiO5 system in geological conditions. Different minerals form at different pressures and temperatures, letting geologists know how deep and/or the temperature at which the parent rock formed.**

EDS users use the term phase much more loosely. A phase is something that is chemically distinct. Our phase maps look at a spectrum pixel by pixel and see how they compare. In the end, the software goes through the entire map and groups each pixel with like pixels. The phase library does chi squared fits to compare the spectrum to the library (figure 2).

Figure 2. Our Spectrum Library Match uses as Chi-squared fit to determine the best possible matches. This phase is based on compositional data, not compositional and structural data.

While the definition of phase is relatively straight forward, the meaning of resolution gets a little murkier. If you asked someone what the EDS resolution is, you may get different answers depending on who you ask. The main way we use the term resolution when talking about EDS is spectral resolution. This defines how tight the peaks in a spectrum are (figure 3).

Figure 3. Comparison of EDS vs. WDS spectral resolution. WDS has much higher resolution (tighter peaks) than EDS, but fewer counts and more set-up are required.

The other main use of resolution, in EDS is the spatial resolution of the EDS signal itself (figure 4). There are many factors which determine this, but the main ones are the accelerating voltage and sample characteristics. This resolution can go from nanometers to microns.

Figure 4. Distribution of the electron energy deposited in an aluminum sample (top row) and a gold sample (bottom row) at 15 kV (left column) and 5 kV (right column). Note the dramatic difference in penetration given by the right hand side scale bar.

The final use of resolution for EDS is mapping resolution. This is by far the easiest to understand. It is just the step size of the beam while you are mapping.

Luckily for us, the easiest way to find out what people mean when they use the terms resolution or phase, is just to ask. Of course, the way to avoid any confusion is to be as precise as possible with your choice of words. I resolve to do my part and communicate as clearly as I can!

** Source: Wikipedia

What’s in a Name?

Matt Nowell, EBSD Product Manager, EDAX

The Globe Theatre

I recently had the opportunity to attend the RMS EBSD meeting, which was held at the National Physics Lab outside of London. It was a very enjoyable meeting, with lotsof nice EBSD developments. While I was there, I was able to take in a bit of London as well. One of the places I visited was the Shakespeare’s Globe Theater. While I didn’t get a chance to see a show here (I saw School of Rock instead), it did get me thinking about one of the Bard’s more famous lines, “What’s in a name? That which we call a rose by any other word would smell as sweet” from Romeo and Juliet.

I bring this up because as EBSD Product Manager for EDAX, one of my responsibilities is to help name new products. Now my academic background is in Materials Science and Engineering, so understanding how to best name a product has been an interesting adventure.

TSL

The earliest product we had was the OIM™ system, which stood for Orientation Imaging Microscopy. The name came from a paper introducing EBSD mapping as a technique. At the time, we were TSL, which stood for TexSem Laboratories, which was short for Texture in an SEM. Obviously, we were into acronyms. We used a SIT (Silicon Intensified Target) camera to capture the EBSD patterns. We did the background processing with a DSP-2000 (Digital Signal Processor). We controlled the SEM beam with an MSC box (Microscope System Control).

Our first ‘mapped’ car.

For our next generator of products, we branched out a bit. Our first digital Charge-Coupled Device (CCD) camera was called the DigiView, as it was our first digital camera for capturing EBSD patterns instead of analog signals. Our first high-speed CCD camera was called Hikari. This one may not be as obvious, but it was named after the high-speed train in Japan, as Suzuki-san (our Japanese colleague) played a significant role in the development of this camera. Occasionally, we could find the best of both worlds. Our phase ID product was called Delphi. In Greek mythology, Delphi was the oracle who was consulted for important decisions (could you describe phase ID any better than that?). It also stood for Diffracted Electrons for Phase Identification.

Among our more recent products, PRIAS™ stands for Pattern Region of Interest Analysis System. Additionally, though, it is meant to invoke the hybrid use of the detector as both an EBSD detector and an imaging system. TEAM™ stands for Texture and Elemental Analysis System, which allowed us to bridge together EDS and EBSD analysis in the same product. NPAR™ stands for Neighbor Pattern Averaging and Reindexing, but I like this one as it sounds like I named it because of my golf game.
I believe these names have followed in the tradition of things like lasers (light amplification by stimulated emission of radiation), scuba (self-contained underwater breathing apparatus), and CAPTCHA (Completely Automated Public Turing test to tell Computers and Humans Apart). It generates a feeling of being part of the club, knowing what these names mean.

Velocity™ EBSD Camera

The feedback I get though, is that our product names should tell us what the product does. I don’t buy into this 100%, as my Honda Pilot isn’t a self-driving car, but it is the first recommendation on how to name a product (https://aytm.com/blog/how-to-name-a-product-10-tips-for-product-naming-success/). Following this logic, our latest and world’s fastest EBSD camera is the Velocity™. It sounds fast, and it is.

Of course, even when using this strategy, there can be some confusion. Is it tEBSD (Transmission EBSD) or TKD (Transmission Kikuchi Diffraction)? Does HR-EBSD give us better spatial resolution? Hopefully as we continue to name new products, we can make our answer clear.

Picture postcards from…

Dr. Felix Reinauer, Applications Specialist, EDAX

Display of postcards from my travels.

…L. A. – this is the title of a popular song from Joshua Kadison which one may like or dislike but at least three words in this title describe a significant part of my work at EDAX. Truth be told I’ve never been to Los Angeles, but as an application specialist traveling in general is a big part of my job. I´m usually on the move all over Europe meeting customers for trainings or attending exhibitions and workshops. This part of my job gives me the opportunity to meet with lots of people from different places and have fruitful discussions at the same time. If I am lucky, there is sometimes even some time left for sightseeing. The drawback of the frequent traveling is being separated from family and friends during these times.

Nowadays it is easy to stay in touch thanks to social media. You send a quick text message or make phone calls, but these are short-term. And here we get back to the title of this post and Joshua Kadison´s pop song, because quite some time ago I started the tradition of sending picture postcards from the places I travel to. And yes, I am talking about the real ones made from cardboard, documenting the different cities and countries I get to visit. Additionally, these cards are sweet notes highly appreciated by the addressee and are often pinned to a wall in our apartment for a period of time.

Within the last couple of years, I notice that it is getting harder to find postcards, this is especially true in the United States. Sometimes keeping on with my tradition feels like an Iron Man challenge. First, I run around to find nice picture postcards, then I have to look for stamps and the last challenge is finding a mailbox. Finally, all these exercises must be done in a limited span of time because the plane is leaving, the customer is waiting, or the shops are closing. But it is still worth it.

It is not only the picture on the front side, which is interesting, each postcard holds one or more stamps – tiny pieces of artfully designed paper – as well. Postage stamps were first introduced in Great Britain in 1840. The first one showed the profile of Queen Victoria and is called “Penny Black” due to the black background and its value. Thousands of different designs have been created ever since attracting collectors all over the world. Sadly, this tradition might be fading. Nowadays the quick and easy way of printed stamps from a machine with only the value on top seems to be becoming the norm. But the small stamps are often beautiful to look at and are full of interesting information, either about historical events, famous persons or remarkable locations.

A selection of postage stamps from countries I have visited.

For me, as a chemist I was also curious about the components of the stamps. Like a famous painting, investigated by XRF to collect information about the pigments and how the artist used them. For the little pieces of art, the SEM in combination with EDS is predestinated to investigate them in low vacuum mode without damaging them. The stamps I looked at are from my trips to Sweden, Great Britain, the Netherlands and the Czech Republic. In addition, I added one German stamp as a tribute to one of the most important chemists, Justus von Liebig after whom the Justus-Liebig University in Gießen is named, where he was professor (1824 – 1852) and I did my Ph. D. (a few years later).

All the measurements shown below were done under the same conditions using an acceleration voltage of 20 kV, with a pressure of 30 Pa and 40x magnification. With the multifield map option the entire stamp area was covered, using a single field resolution of 64×48 each and 128 frames.

Czech Republic Germany

 

Netherlands Sweden

United Kingdom

The EDS results show that modern paper is a composite material. The basic cellulose fibers are covered with a layer of calcium carbonate to ensure a good absorption of the different pigments used. This can be illustrated with the help of phase mappings. Even after many kilometers of travelling and all the hands treating the postcards all features of the stamps are still intact and can be detected. The element mappings show that the colors are not only based on organic compounds, but the existence of metal ions indicate a use of inorganic pigments. Typical elements detected were Al, S, Fe, Ti, Mn and others. The majority of the analysis work I do for EDAX and with EDAX customers is very specialized and involves materials, which would not be instantly familiar to non-scientists. It was fun to be able to use the same EDS analysis techniques on recognizable, everyday objects and to come up with some interesting results.

“Strained” Friendship

Dr. Stuart Wright, Senior Scientist EBSD, EDAX

Don’t just read the title of this post and skip to the photos or you might think it is some soap opera drama about strained relations – instead, the title is, once again, my feeble attempt at a punny joke!

I was recently doing a little reference checking and ended up on the website for Microscopy and Microanalysis (the journal, not the conference). On my first glance, I was surprised to see my name in the bottom right corner. Looking closer, I noticed that the paper Matt Nowell, David Field and I wrote way back in 2011 entitled “A Review of Strain Analysis Using Electron Backscatter Diffraction” is apparently the most cited article in Microscopy and Microanalysis. I am pleased that so many readers have found it useful. I remember, at the time, that we were getting a lot of questions about the tools within OIM Analysis™ for characterizing local misorientation and how they relate to strain. It was also a time when HREBSD was really starting to gain some momentum and we were getting a lot of questions on that front as well. So, we thought it would be helpful to write a paper that hopefully would answer some practical questions on using EBSD to characterize strain. From all the citations, it looks as though we actually managed to achieve what we had strived for.

My co-authors on that paper have been great to work with professionally; but I also count them among my closest personal friends. David Field joined Professor Brent Adams’ research group at BYU way back in 1987 if my memory is correct. We both completed master’s degrees at BYU and then followed Brent to Yale in 1988 to do our PhDs together. David then went on to Alcoa and I went to Los Alamos National Lab. Brent convinced David to leave and join the new startup company TSL and I joined about a year later. David left TSL for Washington State University shortly after EDAX purchased TSL.

Before, I joined TSL, Matt Nowell* had joined the company and he has been at TSL/EDAX ever since. Even with all the comings and goings we’ve remained colleagues and friends.

I’ve been richly blessed by both their excellent professional talents and their fun spirited friendship. We’ve worked, traveled and attended conferences together. We’ve played basketball, volleyball and golf together. I must also brag that we formed the core of the soccer team to take on the Seoul National University students after ICOTOM 13 in Seoul. Those who attended ICOTOM 13 may remember that it was held shortly after the 2002 World Cup hosted jointly by Korea and Japan; in which Korea had such a good showing – finishing 4th. A sequel was played at SNU where the students pretty much trounced the rest of the world despite our best efforts 😊. Here are a few snapshots of us with our Korean colleagues at ICOTOM 13 – clearly, we were always snappy dressers!

* Don’t miss Matt’s upcoming webinar: “Applications of High-Speed CMOS Cameras for EBSD Microstructural Analysis”. 

Common Mistakes when Presenting EBSD Data

Shawn Wallace, Applications Engineer, EDAX

We all give presentations. We write and review papers. Either way, we have to be critical of our data and how it is presented to others, both numerically and graphically.

With that said, I thought it would be nice to start this year with a couple of quick tips or notes that can help with mistakes I see frequently.

The most common thing I see is poorly documented cleanup routines and partitioning. Between the initial collection and final presentation of the data, a lot of things are done to that data. It needs to be clear what was done so that one can interpret it correctly (or other people can reproduce it). Cleanup routines can change the data in ways that can either be subtle (or not so subtle), but more importantly they could wrongly change your conclusions. The easiest routine to see this on is the grain dilation routine. This routine can turn noisy data into a textured dataset pretty fast (fig. 1).

Figure 1. The initial data was just pure noise. By running it iteratively through the grain dilation routine, you can make both grains and textures.

Luckily for us, OIM Analysis™ keeps track of most of what is done via the cleanup routines and partitioning in the summary window on either the dataset level or the partition level (fig. 2).

Figure 2. A partial screenshot of the dataset level summary window shows cleanup routines completed on the dataset, as well as the parameters used. This makes your processing easily repeatable.

The other common issue is not including the full information needed to interpret a map. I really need to look at 3 things to get the full picture for an EBSD dataset: the IPF map (fig. 3), the Phase Map (fig. 4) and the IPF Legend (fig. 5) of those phases. This is very important because while the colors used are the same, the orientations differ between the different crystal symmetries.

Figure 3. General IPF Map of a geological sample. Many phases are present, but the dataset is not complete without a legend and phase map. The colors mean nothing without knowing both the phase and the IPF legend to use for that phase.

Below is a multiple phase sample with many crystal symmetries. All use Red-Green-Blue as the general color scheme. By just looking at the general IPF map (fig. 3), I can easily get the wrong impression. Without the phase map, I do not know which legend I should be using to understand the orientation of each phase. Without the crystal symmetry specific legend, I do not know how the colors change over the orientation space. I really need all these legends/maps to truly understand what I am looking at. One missing brick and the tower crumbles.

Figure 5. With all the information now presented, I can actually go back and interpret figure 3 using figures 4 and 5 to guide me.

Figure 4. In this multiphase sample, multiple symmetries are present. I need to know which phase a pixel is, to know which legend to use.

 

 

 

 

 

 

 

 

 

 

 

 

 

Being aware of these two simple ideas alone can help you to better present your data to any audience. The fewer the questions about how you got the data, the more time you will have to answer more meaningful questions about what the data actually means!

Welcome to Weiterstadt!

Dr. Michaela Schleifer, European Regional Manager, EDAX

The European team had a very exhausting but successful week last week. Some months ago, we discussed the possibility of holding a user meeting at our headquarters in Weiterstadt, Germany. During our stay in Wiesbaden it became a tradition to do at least one user meeting or workshop a year. Because of our move to Weiterstadt and the development of some new structure in the European organization, it took quite some time to plan another user meeting. In spring time, we discussed how to satisfy the different areas in Europe regarding language and also how to transfer information about new technology to our distributors. We finally decided that we should organize 3 different meetings during the week of October 15th. The first two days were for our German speaking customers in Europe, mid-week we invited our distributors and on the last two days we offered a user meeting for our English-speaking customers. There was a lot of organization to be done, like making hotel reservations, preparing presentations, organizing hosting and also booking nice restaurants for the evening events. All of us were a bit nervous about whether everything would work, whether we had forgotten anything important and whether our SEM and system would work properly. The week before the meetings we installed the Velocity™ camera, our new high speed EBSD system in our demo lab and our application people were very happy with the performance and had fun playing around with it.

On Monday October 15th we started our first user meeting in the Weiterstadt office at around 1 pm with customers from the German speaking area. Around 45 participants joined the meeting. At the beginning we gave an overview of our current products and explained that our complete SDD series is using the Amptek modules with Si3N4 windows. Based on some spectra we showed the improved light element performance. After that Felix, one of our application specialists, showed our new user interface APEX™ live and the discussion which arose showed the interest from our users. Although only some users are doing EDS on a TEM we explained a little bit about the differences between EDS on a TEM and on a SEM. We finished the first day with a question and answer session and invited all the participants to a nice location in Darmstadt to have a typical German dinner together.

The next day was completely dominated by EBSD. Our EBSD product manager Matt Nowell, who came from Draper, USA to support us during our meetings, demonstrated the performance of our new Velocity™ EBSD camera. Matt also explained the differences in the camera technology using CCD or CMOS chips and described direct electron detection. It was easy to get more than 3000 indexed points per second while measuring a duplex steel with the Velocity™ camera. Our EBSD application specialist René de Kloe presented a lot of tips and tricks regarding EBSD measurements and analysis of measurement too and did not get tired of answering all the questions. At the end of our program all participants left with a good feeling having learnt a lot and got some good ideas about how to improve their measurements or what they might try to measure on their own samples.

The next day we shortened our program for our distributors and explained our product range and gave live demonstrations of APEX™ software platform and the Velocity™ CMOS EBSD camera. This day was dominated by a lot of discussions with the group and also by questions about our roadmap for 2019.

On Thursday and Friday of this week we did the same program for our English-speaking customers in Europe as we did for the German speaking customers. We had around 15 participants.

During this week we had around 75 customers in our office in Weiterstadt. Each customer was different in his applications and how he uses our systems but what we could observe during the evening was that most of them are very similar in what they like for dinner:

Late on Friday evening the whole European team was very happy that we managed the week with all the meetings and that based on the feedback we got it was a successful week. You may be sure that all of us went home and had a relaxing weekend!

I would like to thank Matt, Rene, Felix, Ana, Arie, Rudolf, Andreas and Paul and especially our customers who gave some interesting presentations about their institutes and the work they are doing there.