[NewCandle] that old glow

[Nick Reiter]

Hey,

So I set up a pop-can bottom aluminum-oxide
luminescence arrangement, using one of the better old
recipes... very dilute phosphoric acid in water...
which gave a bright lemon-yellow light with a hint of
green.  Set this up, ran it at about 130V 100mA for 10
minutes, to get the maximum luminosity level.

The Al surface had its pearlescent sheen I remembered
so well!  I snipped a little square, and chucked it
into the SEM.

I will send pics tonight from my home computer... but
essentially, I was somewhat surprised at what I saw.

The oxide layer looks like a smooth contiguous "glaze"
coating that cracks into a jillion little dried lake
bed mud cracks upon stressing the Al. (Which I had to
do to cut it!)  I was expecting more of a jumble of
crystals or needles.  Ahhhh, but that was only at
1500X or so...  at higher mags, right about where my
capacity to take meaningful photos craps out (around
20,000X) we see that the glaze coating is actually a
coating of baby swiss cheese or sponge!  Little sponge
pores, probably most no bigger than 500 to 1000
angstroms across.

I tried to get some angled shots to see how thick the
macro-layer of Al2O3-ish is... hard to say, my guess
is maybe .5 to 1.0 microns thick?

But next I have to see what the surface of a blue-glow
oxalic or citric acid run piece looks like...

n

The Holy Grail 'neath ancient Roslin waits.
The blade and chalice guarding o'er Her gates. 
Adorned in the masters' loving art, She lies;
She rests at last beneath the starry skies.