phil@amdcad.AMD.COM (Phil Ngai) (02/01/88)
It just hit me that I could build a superconductor in my own garage,
given access to liquid nitrogen. (don't ask why it took so long)
Has anyone reading this done so? Got any good recipes? Sources of the
chemicals needed? (I shouldn't have any problem getting the liquid
nitrogen.) I expect any chemical supply house could provide most of
the ingredients but I've never dealt with one. Do they sell to anyone?
(couldn't that be dangerous?)
I hope this topic hasn't been covered in sci.physics already. Sorry if
it has, but I don't usually read that group, though I will be now.
--
The VT220 keyboard sucks, but the VT320 is usable.
DEC finally got it right!
Phil Ngai, {ucbvax,decwrl,allegra}!amdcad!phil or phil@amd.combeckenba@cit-vax.Caltech.Edu (Joe Beckenbach) (02/01/88)
[]
Phil, about three months ago I posted to some net-group (sci.space?)
some of this information which you request. Here's the gist of it:
Schiecter, Bruce. "How To Make Your Own Superconductors", _OMNI_,
Vol. X, #2 (Nov 1987), pp 72-76.
He gives a cookbook recipe for making an easily-built superconductor
named "123" [Y Ba Cu O ] which can tolerate 99.9% purity of materals.
[ 1 2 3 7+x]
This is a liquid nitrogen superconductor. Several high schools have had
students produce this superconductor with the help of research scientists
from various universities. As the author justly warns, "Please remember,
recipes are rarely complete. The experienced chef knows this and fills in
missing steps unconsciously. The same is true of laboratory recipes. The
consequences of mistakes in the kitchen are only unpalatable; laboratory
mistakes can be dangerous or even deadly."
Ingredients: Copper oxide, barium carbonate, yttrium oxide (these will
be used in proportions of 1-2-3 for the atoms we're interested in. Masses would
come out to 1.13 grams YO, 3.95g BaCO2, 2.39g Cu0 {formulae mine and so not
definitive.} Masses from the article in OMNI.)
Tools: Mortar and pestle, kiln (with oxygenator for last baking),
hydraulic press with 20,000-pound capacity (really 15-18); also, you will need
various support gear (asbestos pads, cleaning supplies [since a contaminated
workarea will ruin the recipe], etcetera).
Grind powders together. Bake 12 hours in kiln at 900-950 degrees C.
[Baking at higher temperatures often means failure.] Let cool inside turned-off
kiln (around 6 hrs.) then regrind the resulting black mass. Place in disk die
and compress in hydraulic press to 15-18 thousand pounds. Result is just barely
a superconductor. To improve performance drastically, rebake in kiln with a
"gentle flow of oxygen" at 950C [time unspecified, possibly another 12 hours],
then let cool VERY SLOWLY ("eight hours at the minimum"-- Schiecter)
I suggest that you locate a copy of this article; there are more items
in the article than the recipe. Good luck.
--
Joe Beckenbach (CS BS '88) I'D RATHER BE ORBITINGfiddler%concertina@Sun.COM (Steve Hix) (02/02/88)
In article <20175@amdcad.AMD.COM>, phil@amdcad.AMD.COM (Phil Ngai) writes: > > It just hit me that I could build a superconductor in my own garage, > given access to liquid nitrogen. (don't ask why it took so long) > > Has anyone reading this done so? Got any good recipes? Sources of the > chemicals needed? (I shouldn't have any problem getting the liquid > nitrogen.) I expect any chemical supply house could provide most of > the ingredients but I've never dealt with one. Do they sell to anyone? > (couldn't that be dangerous?) (I haven't done it myself, but...) A local high school science class has produced high-temperature superconductors at least twice in the past year. (Two different set of students.) You might be able to get them (or the responsible teacher) to give you some information about their method, equipment, suppliers and so on. (Dammned phone books...) Well, try this phone number (it probably isn't the right one, but it should get you started on the right path...the stupid phone book doesn't list which school is where, but I think I got the right street. [I don't live in Gilroy]) 408-842-6414 Good luck. If this doesn't work, blame the Gilroy Dispatch newspaper. :} seh