Sunday, September 30, 2007

Visit by Steve Harris

Well, it's been a while since I posted anything to the blog... sorry about the delay, but I've been busy with some other things. I'll try to post something every day, so that you don't need to worry that your Faithful Bloggist is no longer blog-capable...

The biggest recent event is that Steve Harris, my long-time friend and scientific collaborator from CVD diamond days, stopped by early Saturday morning and we went out to breakfast (at IHOP - the "International House of Pancakes"). Steve lives in Michigan, where he works for a Big 3 automaker in their Research Laboratory. Steve is a physical chemist, and is very well known for work on the chemistry of soot formation, mechanisms for low-pressure diamond deposition, tribology, and probably other areas that I don't know about too...

Steve and I first met shortly after I started working in the field of low-pressure diamond synthesis using Chemical Vapor Deposition (CVD). I'm not 100% sure, but I think we met at the first CVD diamond meeting (of which there would be many more over the next few years...) that I ever went to, which would have been in 1989 in Dallas, TX. Steve was already active in the field when I started, and as I recall he was one of the Invited Speakers at this meeting. We ultimately wrote several papers together, but that was not until a few years later.

[CAUTION: Science ahead! For you non-technical types, you are permitted to skip this section... scroll down until you see "IHOP". To my graduate students: you are not permitted to skip this section...]

One of the first things that drew us together is that I showed by means of simulations that a CH3-based reaction mechanism that Steve had already proposed for low-pressure, low-rate diamond CVD also gave the right growth rates for high-pressure CVD processes such as plasma torches and flames, when one properly accounts for the transport of reactants and products to and from the substrate through the boundary layer. It was thought that some other mechanism must be active in these systems, since there just wasn't enough CH3 in these plasmas or flames to account for the high growth rates - the temperatures were so high that the carbon was tied up in species like C, CH, C2, C2H2, etc. But I showed that right before the substrate, as the gas cools off in the thin (less than 1 mm thick) boundary layer, just enough CH3 is produced to explain the observed growth rates.

For more light reading on this topic, might I recommend...

  • S. J. Harris and D. G. Goodwin, “Growth on the Reconstructed Diamond (100) Surface,” Journal of Physical Chemistry 97 (1), 23-28, 1993 (feature article).

  • D. G. Goodwin, “Simulations of High Rate Diamond Synthesis: Methyl as Growth Species,” Applied Physics Letters 59 (3), 277-279, 1991.

  • S. J. Harris, H. S. Shin, and D. G. Goodwin, “Diamond Films from Combustion of Methyl Acetylene and Propadiene,” Applied Physics Letters 66, 891-893, 1995.


  • OK, now to the important stuff... I had a Country Omelette with pancakes on the side at IHOP. (I have to confess, I don't quite remember what Steve ordered... you now how it is with my memory loss, etc. However, I am happy to report I remember in detail everything about my delicious Country Omelette and the excellent pancakes, which I ate with strawberry syrup.)

    Steve and I had a very good breakfast and a very good visit. Of course we talked some about our current scientific interests - particularly lithium-ion batteries, which, according to an "unnamed highly-placed chemist at a big 3 auto maker" (I won't tell if you won't) are going to be very important for electric vehicles. These batteries work in a very interesting, but poorly-understood way, so there is lots of fun research to do for those who are so inclined...

    But we also talked about "big picture" issues of "what's it all about." I'm not sure we came to any definite conclusions, but we agreed that we liked, in principle, the idea that there is something more to life than just molecules doing what they do... but that's about as far as we got. Maybe this will require multiple IHOP breakfasts to figure out... I'm ready to tackle it: It's a tough job, but someone has to do it.

    Anyway, Steve: thanks for stopping by, and I hope your high school reunion Saturday night went well!

    6 comments:

    Dickie said...

    OK, did you have pi at IHOP, and are it still square, or has somebody updated that.

    Copper's Wife said...

    Man, I was tracking really well with you through the discussion of the high pressure CVD processes, and on into the CH3 mechanisms, but you TOTALLY lost me at the pancakes with strawberry syrup. I'll have to spend some time pondering that ;)

    Glad for your great visit with an old buddy, and to hear how well you are doing! ~ Cheryl

    Verma G said...

    Wow! What a head-spinning entry! I could understand the pancakes and strawberry syrup part, however.

    After going from a "saved" and baptized Baptist, to a searching Unitarian, to a "trusting in the grand plan, whatever it is" kind of philosophy, I can sympathize with the questions asked of Alphie.

    Thanks for getting back to your blog duties and the promise of more.

    Mom

    Emre said...

    that was a great post! just sending a quick hello.
    emre

    RayG said...

    VERY INTERESTING...I mean the part about IHOP. Tell me more about this new diet!

    Dad

    Dave said...

    Dad - I actually am not supposed to lose any weight at least as long as I'm in radiation... They think if I do I might lose energy. I haven't noticed any loss of energy so far, but OK, I'm good with that... bring on the pancakes!