AN ANALYTICAL XRAY SERVICES LABORATORY
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Posted by: In: Uncategorized 30 Mar 2016 0 comments

I’m continually amazed at just how many XRD users we encounter who are only vaguely aware of what their machines can do. These instruments are relatively simple in mechanical terms, but the data they generate can unlock an amazing array of information about the sample. We’ve traveled all over the country over the last 40 years and spoken with countless XRD and XRF users. Many of these are novice users who understand the basics of their application, but little more. Some were relying on courses they’d taken in college many years before. Many had attended one class or another, but rarely felt they came away prepared for the work they’d be doing. I’ve heard so many people describe the information going “straight over my head” that I’m convinced there’s a better way to train users on the broad scope of analyses their diffractometer can perform.

We began offering training classes as soon as we started Texray hoping to fill the gap between tedious trial-and-error and, for some, ineffective large format courses. Along the way we’ve expanded our class offerings to include everything from basic theory (even general chemistry) to advanced analytical techniques such as Rietveld refinement among others. Texray is also certified by MDI to offer field training classes on all their analytical software. This allows us to arrange for demo licenses of some very powerful software for all attendees for the duration of the class.

Flexible:

Many of the clients we’ve worked with have small gaps in their knowledge which leaves them lost on the first day of a large format class. In our small groups, the curriculum is determined by the current knowledge level of the attendees and their own goals. No time needs to be spent on applications which they’ll never use and no one gets “left in the dust” on day one. Multi-stage classes begin with basic theory and progress to advanced techniques to allow for new users to get their feet wet and experienced users to broaden their skills all in a single session. Attendees may jump in and out according to their skill level.

Economical:

When a company is asked to send an employee for outside training, it usually requires a full week of their time during which they’re not covering their usual responsibilities. Travel costs and down time usually mean that a given lab will only send one or two primary users to the training class. With an on-site course from Texray, attendance is unlimited. Training two or more users represents a huge cost savings. There’s no faster or more economical way to bring your whole team up to speed.

Effective:

A highly skilled instructor comes to your site. You’ll work with your own hardware and software to eliminate the learning curve which can become an significant obstacle after large group courses. You’ll receive training targeted specifically to your applications and at a pace dictated by the attendees, not a fixed curriculum. All attendees will be provided with temporary licenses for Jade 2010 software for hands-on work throughout the class.

Posted by: In: Uncategorized 24 Mar 2016 0 comments

I’ve been wanting to write this post for a long time. I think about it every time we get a call or email from someone who wants to talk about an application that’s a little “outside the box” or just making contact to learn more about what we do. The conversation always follows a similar pattern through which they explain what’s needed and I get to offer advice based on my experience, or lack there of, with that type of work. Every time I think I’ve heard it all, I’ll get a call for something completely new. It’s a fascinating world we live in and a great time to be a scientist. That brings me to my point, these callers always seem surprised that when they call, the phone is answered by someone who is technically knowledgeable, at least familiar with the science and quite happy to talk at length about their needs. I tell them all the same thing, “This isn’t just a job, we live for this stuff.”

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CNC machining is a relatively small part of what we do at KSA and Texray, but it’s a personal hobby I enjoy quite a bit. I’ve cut many of these SS branding iron heads friends and charity auctions. They’re fun, not too complicated and really cool.

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Posted by: In: Uncategorized 24 Mar 2016 0 comments

Preventative maintenance has always been a difficult subject for me. The manufacturers all recommend an annual visit to go over their instruments in the hopes that small issues would be dealt with before they became large issues, but it’s never easy to tell a client that their perfectly functional system requires thousands of dollars in maintenance. That being said, over the last 40 years, we’ve performed countless PM routines all over the world on at least 13 different models of XRD and XRF instrumentation and almost every one of those visits has turned up at least one issue which needed attention for one reason or another. This will be the first of several posts detailing various problems we’ve encountered during these visits.

A long time client at one of our most prestigious national laboratories had gone several years without any maintenance being performed on their Siemens D500. Over that time, corrosion built up in this small receiving area before the incident beam optics. I should be very clear that this has no effect on the shutter assembly, fail-safe features or safety in general. However, if left unchecked, flakes will eventually fall into the beam path. The symptom is simply that intensities are lower. This is not the first time we’ve been called out to replace a tube only to find that the low intensities were due to attenuation. Running through a basic PM before installing the new tube saved $6000 of your tax dollars.

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Posted by: In: Uncategorized 07 Sep 2015 0 comments Tags: , , , ,

Every once in a while we get a call for components destined for custom equipment. NIST has built some extremely precise XRD instrumentation from various base components. These are operated in highly controlled environments to qualify certified reference materials (CRM). Some of our other clients have built much more proprietary, but no less impressive systems which I’d love to show in detail if the designs weren’t closely guarded intellectual property.

One of the most interesting and exciting projects we’ve seen recently is the hard-xray monochromator system developed by Dr. Gerald Seidler of University of Washington and his colleagues. The instrument itself has myriad applications, but the general idea is that many experiments which currently require synchrotron time can be performed in a laboratory setting. We’ve worked on other projects like this which were meant more qualification systems to avoid wasting synchrotron time if the experiment didn’t actually require it, but Dr. Seidlers instrument is geared toward bringing XAFS, XES and XANES right into the lab setting.  Read the full paper here.Capture

Posted by: In: Uncategorized 03 Sep 2015 0 comments

There are several key meetings and conferences each year which might concern material scientists in general, but there’s only one exclusively dedicated to analytical X-ray techniques. The Denver X-ray Conference (DXC) has been organized by the International Center for Diffraction Data (ICDD) for the past 64 years! I don’t get to attend as often as I’d like, but I’ve never regretted making the trip. It’s not always in Denver, but The Westin Hotel in Westminster, CO played host yet again this year which makes everything very convenient and relatively inexpensive. I was fortunate enough to merit an invitation from our good friends at Materials Data, Inc. this year and attended as their guest.

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The main draw for me is the educational sessions. Classes taught by legends in the industry on everything from basic XRF and XRD theory to advanced structure determination and pair distribution function (PDF) analysis. Topics vary year to year, but this time I sat in on mainly XRD courses. Instructors are usually prominent university professors or industry experts. ICDD has a strict policy against overt advertising in these sessions which means information is presented in “platform neutral” terms and is beneficial for all attendees. The exhibit hall is full of vendors promoting everything from complete XRF and XRD systems (PANalytical, Bruker, Rigaku, Thermo etc) to sample preparation equipment (Chemplex, Spex, Claisse, Mikron, Angstrom). One of the most interesting products I saw was the latest D2 Phaser from Bruker with a new LynxEye PSD capable of eliminating Cu KB1 peaks without the need for a Ni filter. This doesn’t sound like that impressive of a feat until one considers that this will triple the intensities with an inverse effect on data collection times.

Proto has expanded their offerings to include a benchtop XRD with some impressive capabilities. Most notably, it is the only benchtop I’m aware of which offers independent control of the Theta and 2Theta axes. Grazing incidence and rocking curves are valuable data collection techniques which have thus far been unavailable to small XRD users. It’s always going to be hard for a small instrument to match the data quality of a true, research grade XRD such as the D500, D5000 and D8 lines, but they’ve certainly upped their game in this area.

 

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Oxford was onhand to show off some of their very impressive low temperature stages. The more elaborate offerings are capable of cooling a sample to 12K… You read that correctly, 12 Kelvin. They do this with a regenerative He-based cooling system. I installed a D8 last year at Johns Hopkins which was purchased as nothing more than a base for one of these stages.

 

 

 

I spend most of my time bouncing between industrial, academic and government laboratories maintaining and upgrading their hardware so I see many of the attendees throughout the year though it’s rare to spend time with them casually. It’s always a good time with laughs, enlightenment and education.

 

Posted by: In: Uncategorized 03 Jul 2015 0 comments

We’ve been using additive fabrication (3D printing) and traditional subtractive methods (CNC machining) for years so when we started looking for a fun item to give away at the AAPG conference, we decided that a special Texray/KSA billet Aluminum microsplitter would be a great way to show our prospective clients that we’re not just in the business of chemical analysis, we’re passionate about it.

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It is often quipped that sampling technique is the first and most important step toward accurate results. It’s easy to get carried away focusing on instrumental repeatability and analytical error, but these can only ensure accurate results for the aliquot measured. Some of our clients are only producing materials in mg batches, but we got to talk to the users on the other end of the spectrum at AAPG last month. These geologists are concerned with the chemistry of huge formations so getting a representative analysis is critical. They’ll take thousands of samples and combine the results into extremely complicated data sets. Many of the companies exhibiting there were selling data and data representation tools and nothing else. One company specialized in moving massive quantities of data over existing internet infrastructure. Apparently many of these outfits are generating so much data that the only way to move it rapidly enough is to ship boxes of hard disk drives from the exploration site to the central lab.

Those are extreme cases and require exotic solutions. The more common situation is that a client will ship 1kg of material for us to analyze. Sampling at this scale is still an important part of getting accurate results so while it would be very easy to simply spoon a measurable aliquot from the bag, we prefer a more precise and elegant solution. Microsplitters (also referred to as “rifflers”) are a great way for labs to reduce larger bulk materials with reasonable certainty that the they’ll retain a representative sample. These indispensable little devices consist of a top section (the funnel), a splitting mechanism (I call it the comb), and two or three receptacles (bins). The comb is not simply a series of straight slits, each one has a ramped bottom which alternates between one bin or the other. In this way, the sample is divided between the two bins more or less evenly. The contents of one bin are discarded and the contents of the other bin are dumped into the funnel to be split again until the desired volume is reached. This is why it’s best to have three bins on hand.

The gallery below includes a few pictures from the initial rapid prototyping through the finished product. In the end, I added some fancy legs to the side to make it easier to use. Note that the slits are cut with a slitting saw on out CNC milling machine. This allowed for slots which have rounded edges at the top and bottom. This is critical to avoid clumping and makes a very smooth transition at the top and bottom of the comb. We may offer these as a regular product if there is enough interest to justify a production run. If that happens, customized engraving would be an option. Contact us if you’re interested.

 

Posted by: In: Uncategorized 15 Jun 2015 0 comments

AAPG2015

We had a great time at AAPG 2015. Many of our existing customers were there including some from overseas. The oil industry is in a bit of a slump, but it didn’t stop the big players (Baker Hughes, Weatherford Labs, Core Labs, Saudi Aramco, etc) from putting together very impressive booths and lots of extra activities.

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We will be exhibiting at this year’s American Association of Petroleum Geologists Annual Conference and Exhibition (AAPG ACE 2015) in Denver, CO from May 31-June 3.

Stop by our Booth #2152, speak to our team of experts, and check out video demos of what is happening at Texray. We will be handing out gifts and hosting a contest for some great prizes.

We look forward to seeing you there. If you are interested in attending but have not registered, Contact Us on how you can get a FREE Exhibit Registration. 

The majority of the samples we receive come in volumes high enough to completely fill the well in any of our standard sample holders. Some are too large or oddly shaped which calls for a special holding solution like those listed here, but many are simply very small quantities of powder. Placing these in a standard holder would leave them well outside the plane of diffraction and provide terrible data, not to mention substantial scatter
or diffracted background from whatever the powder is placed on. The answer is a zero background sample holder (ZBH). Most our users at KS Analytical Systems run the original Siemens/Bruker plates, but others are using Si(100) and even glass substrates. We’re very happy to say that
we’re able to offer a direct replacement for these with our new ZBH-32 holders. These fit most Siemens XRD systems and can be customized for use in most any other system. Contact us for more information on this. The scan below shows the data collected from a single mg of Silicon 640B standard powder spread across a ZBH.

Off Planar Quartz ZBH w-1mg 640B

Full scan of 1mg Silicon 640B standard spread across a ZBH

ZBH-32

ZBH-32 sample holders mounted for Siemens and Bruker single sample stages.

 

Some users report acceptable results using simple glass plates. While there are serious caveats here, it may be a reasonable solution for some users. The issue with amorphous glass is not diffracted peaks in the background, but rather, scatter off the surface. X-ray scattering off a surface is inversely proportional to the average atomic number of that material. That is to say, the lighter the matrix, the more efficiently it will scatter X-rays. This is why we use a pure Graphite sample to characterize the emission spectra of our XRF instrumentation. The glass sample shows the expected scatter “hump” starting at a very low angle and it doesn’t flatten until nearly 100°2Θ. While some of this can be modeled and subtracted with good profile fitting software like Jade 2010, it can be challenging to match the data quality of a good ZBH. We’re working on a series of videos to guide new users through some of these features, but on-site training classes are also available.

 

Glass plate

Amorphous glass empty

Glass-Qtz-Si510 overlay

Glass, ZBH-32 and off-planar quartz scans overlayed for comparison

 

 

 

 

 

 

 

 

Several of our customers in the geological industry use standard Si(100) wafers. These can be a great solution, but again have serious drawbacks for some applications. The Si(100) material creates diffracted peaks which are very sharp and therefore easier to model out sometimes, but also very high as the material is monocrystalline. The scan below shows what happens when one tries to run a normal scan across a bare plate. The largest peaks are actually only one or two which have over loaded the detector and caused it to drop out. All of these scans were collected with our SDD-150 which can handle up to 1×10^6 cps, but for the sake of good comparison, we left it tuned as it would be for a standard pattern. The monocrystalline nature of this material causes big problems, but it also allows for a creative solution. See the second scan for the results of the same measurement with the plate angled 1 degree off of theoretical. With this geometry, it’s unlikely this would affect the data quality dramatically, but the offending peaks are drastically diminished.

 

Si-100 wafer

Si-100 empty

Si-100 locked vs unlocked

Si-100 standard vs skewed scan

 

 

 

 

 

 

 

 

 

 

Off-planar Quartz holders have been the industry standard for decades. Historically, these have been made from solid, monocrystalline quartz material cut at a specific angle (6° off the C axis if I’m not mistaken). While these work well, they can be inconsistent. Even some of the OEM holders we’ve tested have shown some peaks which we can’t explain. Talking to some very experienced crystallographers, we find that they’ve had similar experiences.

 

 

Off Planar Quartz ZBH

Off-planar Quartz empty

ZBH-32 empty

ZBH-32 empty

 

 

 

 

 

 

 

 

We’ve been looking for a better answer for several years, but there are few off-the-shelf materials which work as well as off-planar quartz. The ideal answer was to cut solid Si(100) oriented billets such that the face presented to the diffractometer had no d-spacings which would diffract in the normal range of these machines. This is not unlike the off-planar Quartz method, but the starting material is much more consistent and durable. Si(510) offers very low background as well as the consistency of a manufactured product. The new ZBH-32 sample holders from KSA come in two versions, ZBH-25 and ZBH-32 with the latter being ideally suited for rotating stages and low angle work.

 

 

 

 

20141124_161938Our recent sealed sample cell project required a thin covering film to be applied over loose powder before analysis by XRD. We tested a few options for this film as part of the design process and the results were interesting enough that we thought it would be worth dedicating a full post to that data and expanding the range of materials a bit to satisfy our curiosity.

All data was collected on our primary powder system. This is a Siemens D5000 configured with a theta/theta goniometer, automatic anti-scatter and divergence slits, a standard sealed Cu tube (LFF) and our new KSA-XRD-150 detector system. We alternate between a digital phi stage, 40-position autosampler and the standard, single sample stage which was used in these experiments. I had a spare sealed-sample cell available which made it easy to exchange the films without disturbing the sample surface. The design of these stretches the film taught each time the cell is assembled. I’d originally tried to simply lay the film over a side-load holder, but without being tightly held, it would buckle enough that results at low angles were probably affected. A NiO standard powder was used due to its high purity and compositional difference from any of the film materials.

The data clearly shows that Polyimide was the best choice for this application as it resulted in very limited attenuation as well as an extremely minimal increase in background intensity/amorphous scatter. Some of the other patterns were very interesting though.

20141124_161656 NiO CONTROL No film

 

 

 

 

 

 

 

 

 

NiO Prolene copy NiO Mylar copy

 

 

 

 

 

 

 

 

 

NiO Polycarbonate copy NiO Polyimide copy

 

 

 

 

 

 

 

 

 

 

NiO Polypropylene copy

 

 

NiO Prolene

Scotch “Magic” office tape. Adhesive side down.

NiO Scotch packing

Scotch “Heavy duty” packing tape. Adhesive side down.