Nanowires made, waiting for SEM TuesdayPosted on June 19th, 2009 1 comment
We finally fixed the problem we’d been having with making nanowires, which turned out to be a broken reference electrode. Ideally, the part can take a consistent measure of potential differences regardless of what it is submerged in, which is important to (i) successful electrodeposition and (ii) consistency. So while our early nanowire growths were (as the kids might say) full of fail, with a new reference electrode, all became well.
I wound up making 8 different samples, including one pure Ni and one pure Fe, as well as six intermediate values. The pure Fe one seems little janky. Due to the electronegativity differences between Ni and Fe, the final composition ratios will end up a bit random-looking (not a clean 0:6, 1:5, etc.), but if we compensated correctly, they should be dispersed fairly evenly.
Tuesday, I will get to go to SIU’s imaging center where I’ll assist our lab’s post-doc in taking some pictures of the wires. This will be very similar to the last time I encountered an SEM, except that instead of one successful growth we have eight; it will probably take a long time. Then we’ll leave the samples with the imaging people to perform electron dispersion spectroscopy (EDS) to find the ratio of Ni to Fe in each of the samples. Here’s to hoping no Fe crept into the “pure Ni” sample!
Yesterday, I etched all of the samples. It’s a fairly simple process, but it took a few rounds of practice to get right (I will only be sure that I did in fact get it right on Tuesday). The templates we’re using dissolve in NaOH. Today I prepared them for the SEM, and they are presently good to go.
Magnetic measurements have begun, but I haven’t received all of the necessary training yet. Here’s to hoping for fast progress.
The project has received an addendum. Once I find the alloy with the most favorable magnetic qualities, I will take the solution, make more samples of various diameters, and find an optimized diameter.
The last week has been rather odd. Fortunately, everything has been working (finally). However, there was an electrician in the lab doing rewiring on Tuesday and Wednesday which hampered progress. Wednesday night and yesterday, I did a lot of work to get all of these samples fabricated and prepared, but that left a meager workload for today. This is fortunate because I had a minor alarm clock malfunction. It is also unfortunate because I find myself writing a blog entry instead of laying down some science.
Happy Father’s Day. I get to spend the weekend in St. Louis with my family. I’m going to experiment with route selection from Carbondale to St. Louis. Illinois State Highway 13, you had better be worth it.
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