EDS

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.

A Lot of Excitement in the Air!

Sia Afshari, Global Marketing Manager, EDAX

After all these years I still get excited about new technologies and their resulting products, especially when I have had the good fortune to play a part in their development. As I look forward to 2019, there are new and exciting products on the horizon from EDAX, where the engineering teams have been hard at work innovating and enhancing capabilities across all product lines. We are on the verge of having one of our most productive years for product introduction with new technologies expanding our portfolio in electron microscopy and micro-XRF applications.

Our APEX™ software platform will have a new release early this year with substantial feature enhancements for EDS, to be followed by EBSD capabilities later in 2019. APEX™ will also expand its wings to uXRF providing a new GUI and advanced quant functions for bulk and multi-layer analysis.

Our OIM Analysis™ EBSD software will also see a major update with the addition of a new Dictionary Indexing option.

A new addition to our TEM line will be a 160 mm² detector in a 17.5 mm diameter module that provides an exceptional solid angle for the most demanding applications in this field.

Elite T EDS System

Velocity™, EDAX’s low noise CMOS EBSD camera, provides astonishing EBSD performance at greater than 3000 fps with high indexing on a range of materials including deformed samples.

Velocity™ EBSD Camera

Last but not least, being an old x-ray guy, I can’t help being so impressed with the amazing EBSD patterns we are collecting from a ground-breaking direct electron detection (DED) camera with such “Clarity™” and detail, promising a new frontier for EBSD applications!
It will be an exciting year at EDAX and with that, I would like to wish you all a great, prosperous year!

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.

Endless Summer

Matt Nowell, EBSD Product Manager, EDAX

My family and I love the beach. We love to swim in the water, ride the waves, and play in the sand. Each summer we typically spend time at Sunset Beach, North Carolina. After years of seeing the cool stuff in the SEM, materials science and microscopy are always topics of discussion. This year, after enjoying the musical Hamilton, my wife was inspired to start working on a periodic table of elements rap song. My 13-year-old learned more about metalworking watching the History Channel show, Forged in Fire, where participants are challenged to make different weapons from assorted metallic sources. My favorite part was watching them evaluate different parts of a bicycle for heat-treatable steel to recycle. One of my favorite moments though was unpacking my beach shoes on the first day.

Generally, when we visit a beach, we try to bring home a shell or a piece of driftwood. However, when I was putting on my shoes for the first time, I noticed some sand was still present. My last beach trip had been to the Cayman Islands. I immediately noticed that this sand looked much different than the sand at Sunset Beach. I decided to save a little bit of each for some microscopy and microanalysis when I got back home.

When I looked at them both more closely, I saw that the sand from Sunset Beach (SB) on the left was much darker with black flecks, while the sand from Grand Cayman (GC) was much lighter. Thinking about the possible composition of the sand got me thinking about the bladesmithing competition held at the TMS annual meetings. One year, the team from UC Berkeley created a sword using magnetite found at local beaches using magnets. I thought it would be interesting to examine both of these sands with my SEM, EDS, and EBSD tools.

Sand grains from Sunset Beach
Sand grains from Sunset Beach.
Sand grains from Grand Cayman
Sand grains from Grand Cayman.

 

Initially I placed a bit of sand on an aluminum stub for SEM and EDS analysis. To reduce charging effects, I used the Low Vacuum capability of our FEI Teneo FEG-SEM, running at 0.1 mbar pressure. Images were collected using the Annular BackScatter (ABS) detector for atomic number contrast imaging. The sand grains from Sunset Beach were generally a little smaller than the Grand Cayman sand, as expected from visual inspection. Both sands exhibited cracking and weathering, which isn’t surprising in hindsight either. Many grains show flat surfaces, with internal structure visible with ABS imaging contrast.

I followed the imaging work with compositional analysis using EDS. The Sunset Beach sand was primarily composed of silicon and oxygen grains, which I suspect is quartz. The single brighter grain in Figure 3 was composed of an iron-titanium oxide. The Grand Cayman sand was primarily a calcium carbonate (Ca-C-O) material. The more needle shaped grains were primarily sodium and chlorine, which I assume is then salt that has solidified during the evaporation of the water. All this leads me to believe I really didn’t do a good job of cleaning my shoes after Grand Cayman.

While quartz being present in sand wasn’t surprising to me, the observation of calcium carbonate did remind me of some geological homework I did on the island. The water in Grand Cayman was very clear, which made it great for snorkeling. We swam around and saw a coral reef, a sunken ship, lots of fish, and stingrays. To understand why the water was so clear, I read that it was the lack of topsoil, and the erosion and runoff of topsail to the water that was responsible for the clarity. Looking again at this reference, it mentions that the top layer of the island is primarily composed of carbonates. The erosion of this material would explain the primary composition of the beach sand in my shoes.

Of course, the next step now is analyzing these sands with EBSD to determine the crystal structure of the materials. I’ve started the process. I’ve mounted some of the sand in epoxy, and hand polished to get some flat surfaces for analysis. I’m able to get EBSD patterns, but getting a good background is going to be tricky. I think the next step will be to watch my colleague Shawn Wallace’s webinar on Optimizing Backgrounds on MultiPhase samples to be presented on September 27th. You can also register for this here.

In the meantime, I’ll keep the sand samples on my desk to remind me of summer as the colder Utah winters will be approaching. It will be a good reason to stay inside and write the next chapter of this analysis for another blog post.

One, Two, Three Times an Intern

Kylie Simpson, Summer Intern at EDAX

Kylie ‘at home’ in the Applications Lab.

This summer was my third working for the EDAX Applications Team. It has been an amazing opportunity to be directly involved with research, customer support, and software testing here in Mahwah. I was able to continue with the APEX™ software testing that I worked on last summer which I found incredibly interesting because I’ve been able to observe the software evolve to best meet customer needs and improve in overall performance. I also had the chance to attend the Microscopy and Microanalysis (M&M) show in Baltimore, MD. This was an incredible experience for an undergraduate student, like me, interested in Materials Science and Microscopy. I was able to connect with people in the field, attend talks on topics at the forefront of Microscopy research, and present a poster that I have been helping out with this summer here at EDAX.

The majority of my time this year has been focused on helping Dr. Jens Rafaelsen, the head of the Mahwah Applications Team, with the data collection and analysis for a paper on the effects of Variable Pressure on EDS. Although Variable Pressure is an incredibly useful tool for studying SEM samples that are susceptible to charging, the introduction of gas to the specimen chamber has implications that must be considered when collecting EDS spectra. Additional gas particles in the SEM chamber lead to a scattering of the electron beam, known as beam spread or beam skirting.

In order to study and quantify this phenomenon, we used a double insulated Faraday cup with a 10 µm aperture, pictured below, to measure the unscattered beam at different pressures and working distances. We also modeled this beam scattering using Monte Carlo simulations that consider the SEM geometry as well as the type of gas in the chamber, which vary based on the type of SEM. Based on our experimental and theoretical results, we determined that as much as 85% of the electron beam is scattered outside of the 10 µm diameter high pressures of 130 Pa. This is much more scattering than we had anticipated, based on previous papers on this subject, making these results incredibly important for anyone using variable pressure in the SEM.

Double insulated Faraday cup with a 10 µm aperture.


Unscattered Beam Percentage vs. Pressure: Theoretical

Unscattered Beam Percentage vs. Pressure: Experimental

Overall, I am very thankful for the opportunities that EDAX has given me this summer and in the past. As a member of the Applications Team, I was able to work alongside the Engineering, Software Development, Customer Support, and Sales teams in order to help provide customers with the best analysis tools for their needs. I also gained a deeper understanding of the research, data collection, and analysis processes for writing a paper to be published: a truly incredible experience for an undergraduate student. Above all, the plethora of knowledge and experience of those here at EDAX and their willingness to share this information with me and others has been the most valuable aspect of my time here.

Crown Caps = Fresh Beer?

Dr. Felix Reinauer, Applications Specialist Europe, EDAX

A few days ago, I visited the Schlossgrabenfest in Darmstadt, the biggest downtown music festival in Hessen and even one of the biggest in Germany. Over one hundred bands and 12 DJs played all kinds of different music like Pop, Rock, Independent or House on six stages. This year the weather was perfect on all four days and a lot of people, celebrated a party together with well known, famous and unknown artists. A really remarkable fact is the free entrance. The only official fee is the annual plastic cup, which must be purchased once and is then used for any beverage you can buy in the festival area.

During the festival my friend and I listened to the music and enjoyed the good food and drinks sold at different booths in the festival grounds. In this laid-back atmosphere we started discussing the taste of the different kinds of beer available at the festival and throughout Germany. Beer from one brewery always tastes the same but you can really tell the difference if you try beer from different breweries. In Germany, there are about 1500 breweries offering more than 5000 different types of beer. This means it would take 13.5 years if you intended to taste a different beer every single day. Generally, breweries and markets must guarantee that the taste of a beer is consistent and that it stays fresh for a certain time.

In the Middle Ages a lot of people brewed their own beer and got sick due to bad ingredients. In 1516 the history of German beer started with the “Reinheitsgebot”, a regulation about the purity of beer. It says that only three ingredients, malt, water, and hops, may be used to make beer. This regulation must still be applied in German breweries. At first this sounds very unspectacular and boring, but over the years the process was refined to a great extent. Depending on the grade of barley roasting, the quantity of hops and the brewing temperature, a great variety of tastes can be achieved. In the early times the beer had to be drunk immediately or cooled in cold cellars with ice. To take beer with you some special container was invented to keep it drinkable for a few hours. Today beer is usually sold in recyclable glass bottles with a very tight cap keeping it fresh for months without cooling. This cap protects the beer from oxidation or getting sour.

Coming back to our visit to the Schlossgrabenfest; in the course of our discussions about the taste of different kind of beer we wondered how the breweries guarantee that the taste of the beer will not be influenced by storage and transport. The main problem is to seal the bottles gas-tight. We were wondered about the material the caps on the bottles are made of and whether they are as different as the breweries and maybe even special to a certain brewery.

I bought five bottles of beers from breweries located in the north, south, west, and east of Germany and one close to the EDAX office in Darmstadt. After opening the bottles, a cross section of the caps was investigated by EDS and EBSD. To do so, the caps were cut in the middle, embedded in a conductive resin and polished (thanks to René). The area of interest was the round area coming from the flat surface. The EDS maps were collected so that the outer side of the cap was always on the left side and the inner one on the right side of the image. The EBSD scans were made from the inner Fe metal sheet.

Let´s get back to our discussion about the differences between the caps from different breweries. The EDS spectra show that all of them are made from Fe with traces of Mn < 0.5 wt% and Cr, Ni at the detection limit. The first obvious difference is the number of pores. The cap from the east only contains a few, the cap from north the most and the cap from the middle big ones, which are also located on the surface of the metal sheet. The EBSD maps were collected from the centers of the caps and were indexed as ferrite. The grains of the cap from the middle are a little bit smaller and with a larger size distribution (10 to 100 microns) than the others, which are all about 100 microns. A remarkable misorientation is visible in some of the grains in the cap from the north.

Now let´s have a look at the differences on the inside and outside of the caps. EDS element maps show carbon and oxygen containing layers on both sides of all the caps, probably for polymer coatings. Underneath, the cap from the east is coated with thin layers of Cr with different thicknesses on each side. On the inside a silicone-based sealing compound and on the outside a varnish containing Ti can also be detected. The cap from the south has protective coatings of Sn on both sides and a silicon sealing layer can also be found on the inside. The composition of the cap from the west is similar to the cap from the east but with the Cr layer only on the outside. The large pores in the cap from the middle are an interesting difference. Within the Fe metal sheet, these pores are empty, but on both sides, they are filled with silicon-oxide. It seems that this silicon oxide filling is related to the production process, because the pores are covered with the Sn containing protective layers. The cap from the north only contains a Cr layer on the inside. The varnish contains Ti and S.

In summary, we didn’t expect the caps would have these significant differences. Obviously, the differences on the outside are probably due to the different varnishes used for the individual labels from each of the breweries. However, we didn’t think that the composition and microstructure of the caps themselves would differ significantly from each other. This study is far from being complete and cannot be used as a basis for reliable conclusions. However, we had a lot of fun before and during this investigation and are now sure that the glass bottles can be sealed to keep beer fresh and guarantee a great variety of tastes.

It came from outer space!

Dr. Jens Rafaelsen, Applications Engineer, EDAX

One of the interesting aspects of being in applications is the wide variety of interesting samples that you come across and this one came up when I was looking for a sample for an upcoming webinar, where I needed some ‘pretty’ maps. Our US EBSD applications engineer Shawn Wallace was previously at The Department of Earth and Planetary Sciences at the American Museum of Natural History in New York and consequently he knows quite a bit about space rocks. He handed me a thin section of a meteorite labeled NWA 10296 (more information at https://www.lpi.usra.edu/meteor/metbull.php?code=62421) and it did not disappoint.

There were a lot of interesting features in the sample, but I ended up concentrating on one of the large chondrules shown below.

Figure 1. BSE image

The primary composition of the sample is olivine (magnesium iron silicate) and the maps below show a high concentration of the Mg internal to the chondrule with an outer perimeter low in Mg and Si. The iron within the chondrule is forming particulates with low content of O and some veins of Al is also seen while the outer perimeter is an iron oxide.

Figure 2. Mg, Si and O maps (left to right).

My astronomy classes are long behind me and I can’t claim to be able to extract deep insight as to the formation and origin of this meteor but regardless, there’s something fascinating about looking at some of the early matter of the universe. As I heard Emma Bullock phrase it at the Lehigh Microscopy School, “It might just be an old rock, but it’s an old rock from outer space!”.

Figure 3. Fe (left) and Al (right) maps.

The upcoming webinar is less about space rocks and more about mapping and data representation so if this has your interest, please join us April 11 2018. Click here to register . Alternatively you can always find past webinars on our homepage https://www.edax.com/news-events/webinars