Allen J. Hall

Materials Science & Engineering, Productivity, and Life

Author Archives: Allen H.

Long in the tooth graduate student in Materials Science and Engineering. My original area of study (UG and Grad) was Polymers. I moved to semiconductors/photovoltaics about mid-stream into my PhD. I’m finding the more I learn, the more I realize how much I don’t know.

This blog will hopefully focus on topics related to productivity, materials science, and general motivational work. I’ll try to keep the general life stuff elsewhere.

I’m not new to this blogging thing, but it’s a new idea to have my name out there, and to share my thoughts in a bit more personal way with you, my kind reader.

Likely postings to this blog will be few and far between. There’s just too much to do in life, and we all have to set our priorities. :) Which brings us back somewhat to the purpose of this blog- to share with you my thoughts on productivity.

I hope you pull up a chair and enjoy. Don’t hesitate to be in touch.

Prof. Janice Tomasik – Chemistry Education

Prof. Janice TomasikMy sister, Janice, got a great mention in C&E News! She is a professor at Central Michigan University in Chemistry. Her studies and research are in Chemistry Education. Read More »

Part III: Matlab Function for Xpert XRD Reciprocal Space Mapping

A series of MATLAB functions will follow. Some of these “.m” files call each other, so ensure you have all of them before you start.

The purpose of this file is to load in all the .x00 files in a directory of Omega-Omega-2-Theta slices for reciprocal space mapping of a sample. “OmegAxis” determines the scale for the Omega axis (y) for reciprocal space mapping. [again, this is not yet in Q-space, that will come at a later date]

The first function loads data into your workspace for a directory of .x00 files that have a common base filename. The user needs to supply the first index number and last index number for loading the files. The program then attempts to load “filenameIndex.x00″ in a linear fashion for all .x00 files of that filename indexed in the cd’d directory. [Change directory to the working directory needed before starting this function.]

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Part I: MATLAB Functions for Philips XPert XRD Files

I decided here and there to publish various MATLAB functions I’ve written for my own work. There’s just one caveat- each one of these is a serious work in progress. In fact, they may not progress much more than what is disclosed here since they get the job done for me.

But, I felt that this likely would help a few people who are trying to do the same type of thing, and I’d rather ease those who come after me, and give them a slight step ahead if possible.

For those of you with old version of the Philips XPert XRD software (specifically those who can’t output in XRDML files), I offer a crude import function for simple scans.

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Happiness and Meditation (quick one for Michele)…

This is a quick post for Michele. A sort of aggregated post. I’ll have to add more in the future regarding where this comes from. Essentially, I’ve been intrigued in the past few years by the work going in conjunction with the Mind and Life institute. This institute is trying to bring about collaboration between Buddhist practitioners and Science Researchers. I myself am not Buddhist, but appreciate some of their intellectual pursuits.

Mattieu Ricard getting his EEG

In particular, I came across the work of Matthieu Ricard (who’s called the Happiest Man On Earth- what a title… must have serious responsibilities!). Videos for you after the link…
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Some thoughts on Productivity: my history and interests…

I find myself in the strange position of starting a new blog on a new site.  More professionally focused, less fluff if possible, to the point, more easily read; all these things come to mind when I think about what I’m wanting to do here.  Ultimately, it’s all about content and helping others with similar interests find possible solutions to what they are working through.  Having already discussed many items regarding productivity in the past, I’m finding I may be covering old ground anew.  But, I finally have a home here, and so I have to sweep away the cobwebs, polish the floor, find my furniture, and get things started.  This, an opportunity to start fresh, and tell you my thoughts on productivity approaches, and what has worked for me, and how I (like everyone) struggle with various aspects of pushing myself to success. (Read about the two books that have influenced my thoughts on productivity the most after the jump…)
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Quick One: UIUC Thesis Class Breaks ChapterBib (LaTeX)

I could not decide exactly how to post this… searching high and low, I couldn’t find the answer to my problem. I felt, in the very least, it needed to be posted here. So, I’ve decided to focus on the problem only. Then, in a future post, I’ll describe in more detail how I go about doing my research writing using LaTeX [wikipedia]. So, my basic comment is: I write in LaTeX, BibTeX, etc., and the following will help only a few people doing the same, and doesn’t actually offer a solution right now. :) [Boy, aren't I helpful?]  (click through to read more…)

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World’s Largest Materials Science Demo?

For the Materials Scientist, a very interesting event happened on Monday 6/9/08.  The Los Angeles department of water and power inadvertantly may have created the largest Materials Science demo of crystal stacking, defects, and boundaries when they placed 400,000 balls onto the surface of the Ivan Hoe Reservoir.  [Read the original news release (including video) by the LA Times (images from LA Times) or the blog post at Design Verb where I found out about it.]

Bubble Raft On Lake Ivanhoe

The balls are being placed on the surface of the lake in order to prevent the formation of various forms of bromates [wikipedia].  The bromates are forming due to the presence of both chlorine and bromine in the water coupled with the presence of sunlight.  Local public officials hope that the balls will help block sunlight from the lake-water and prevent the bromate formation.  [Let's hope that heat doesn't form it either- those balls are going to get really hot with the sun blaring down on them!]

The balls on the surface of the lake is almost exactly like a model often used as a class-room demo called a “Bubble Raft” [wikipedia].  The model describes in 2 dimensions (usually) the concepts of crystallites (polycrystals), grain boundaries, and dislocations.  The more common demonstration is table-top consisting of a large number of bubbles on the surface of a thick liquid like glycerin.

Bubble Raft

There are even published articles utilizing this approach as a model system for indentation measurements etc.  Other common places to see this phenomonon is when you get a pop from the machine (clear-plastic bottle), you may see bubbles form various areas of ordered stacking.  Of course, the structure of the pop-bottle bubble raft is quite complex- stacking faults and dislocations abound.

Bubble Raft On Lake Ivanhoe

If you look closely at the above image, you’ll notice that there are a number of areas where the balls are all stacked nicely in 2D, and then a little further away, a different orientation of stacking… when these two meet, there’s a “grain boundary”[wikipedia].  In fact, this is exactly what a polished and etched sample of polycrystalline metal looks like in a reflected light microscope.  Of course, in a sample like that, you can’t see the atoms at all, but just regions of different reflectivity.  (See how the lightness/darkness of the “crystallites” are different?)  Little lines in the microscope show the boundaries (often acid etching is required to see them).  Of course, if you have a transmission electron microscope (TEM), for instance, you actually *can* see stacks of atoms and grain-boundaries!  [There is a world-class Aberration Correction TEM available at the FS-MRL where I currently do research.  Hopefully I'll be able to use it to get some excellent images to share.]

Frequently in Science we find beauty in the things around us.  Along with all this beauty is some natural function or rule, often unique and interesting.  All you have to do is keep your eyes open, walk a bit slower, and enjoy the walk (or bounce as the case may be)!

Balls bouncing down to Lake Ivanhoe

Published in the Journal of Applied Physics…

Well, I’m finally published in my current field.  It took a very very long time to get this paper published.  All sorts of reasons for the delay.  In fact, this work was originally started in 2004  (our first bicrystal was successfully grown in ’04).  During research group meeting, I made an under the breath comment something akin to: “Well, darnit, it’s too bad we can’t study a single grain-boundary, because then everything would be so much easier…”  Prof. Rockett looked over to me and smiled: “But, Allen, we can study a single grain-boundary!  That’s a great idea!”  So, the bicrystal project was started.

We were able to obtain a bicrystal GaAs wafer from Wafer Technology Limited Co. (UK); I requested a bad growth, with crystallites as large as possible.  I’ll be forever indebted to the great guys at Wafer Technology for their quick grasp of what I was looking for.  After visiting our group in 2006, S. Seibentritt at HMI (now at Lüxenbourg) started similar work.

While this current paper isn’t perfect, it went through numerous revisions.  Most of the extensive EBSD calculations didn’t make the paper.  Subsequent papers will likely revisit the disorientation discussion.

Epitaxial growth of very large grain bicrystalline Cu(In,Ga)Se2 thin films by a hybrid sputtering method
J. Appl. Phys. 103, 083540 (7 pages) (2008)

Unfortunately, there was an error we missed in the proof.  The paper is currently missing Figure 2(c): The cross-sectional HRTEM image (the hard work of C. Lei).  The image can be found here: Cross-Sectional HREM image of Cu(In,Ga)Se2 bicrystal, hosted at Prof. Angus Rockett’s research group’s webpage.

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Making today a good day.

(written on Saturday)

Last night’s shindig has me quite tired today.  I think I haven’t slept too well, and yet there was so much to do, I couldn’t let myself waste the whole day.  The sun is shining outside like it hasn’t in ages.  Chel and I headed out to snag this summer’s plants (mostly flowers and a few tomatoes etc.).  A much previously discussed and needed chore.

Today, even though I had lack of sleep, I found it to be a joy, not a chore.  Starting last night I put out a recipe for blueberry pancakes, prepped the blueberries, and prepared for the AM.  We finally actually made pancakes together (America’s Test Kitchen BlueBerry Pancakes).  They hit the spot completely- wonderful batter, melted butter and a hearty helping of Maple Syrup.  I decided to forgo putting them all together before eating, so we ate standing up beside the griddle.  It was uncouth, for sure, but it was exactly what was needed after poor sleep.  The smile shaped up on Chel’s face after that (guess sugar in the AM is a good thing), and we planned our day- Farmer’s Market, then to FS to pick up flowers.

That’s what we did, and the smile on her face picking out various plants for the containers on the back porch told me that despite my extreme tiredness, it was more than worth the struggle to have her in a great mood.  We accidentally got the owner with our questions about planting, etc., and she was more than kind paying attention to us with our silly questions.  I apologized for taking her time up with small things and she said: “Well, that’s what got me here today… helping folks like you enjoy planting.”  (paraphrased)

So, now it’s off to snag some soil and mix up the cool new polyacrilamide crystals into it to help the direct-sunlight containers.  That reminds me, I need to do a bit of research on polyacrilamides- wondering if they’re just drying out hydrogels and selling them dry…

Sorry for the mundane post, but I figured a story would be better for the first go than another Hello World.  ;)

I hope to have a lot more useful items up on the blog soon.  Thank you for stopping in for a quick read!


ps- Today was a day I realized that some days you can Make good days just by your choices in actions and care for others.  Sure, I could have stayed in bed, but I now have a happy gal on my hands, and just that is helping my own day totally rock.  [Not to mention our back porch is looking excellent!]

A Quick Introduction...

I'm a graduate student (PhD Candidate) at the University of Illinois at Urbana-Champaign.

I've studied and researched in two fields of Materials Science and Engineering (Polymers and Semiconductors). My interests are as diverse as my musical tastes and I usually have my hand in some crazy project during my free time.

I'm available for consulting and have access to a world-renown materials research user-facility supported by the D.O.E. If you would like to know more, please contact me.

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