The naughty magnet

Magnetite, mixed-valence ferrites in general, are supremely insoluble
in any non-reactive solvent. Adding a jot of hydrazine to boiler
steam semi-reduces iron oxides and plates out magnetite inside pipes.
This passivates them against further corrosion. The idea of
non-reactively dissolving and recrystallizing cm-sided magnetite
cystals near room temperature is madness. However...

Magnetite is nicely soluble in ambient temp 2:1 urea/choline chloride
- a 178 degree freezing point depression from the weighted-average
melting points of the components. It goes up, it comes out.
Potentially cute high school science project with magnetite or barium
ferrite. Heat it up to dissolve solute, slowly cool to get seed
crystals. Then go for Big Casino. Do ya think a clean crystal of
magnetite will be transparent (transparent colored, of course)? Could
be a mammoth refractive index from polarized magnetic coupling.

http://sciencekit.com/images/250/1737-40WebF.jpg
Thiele-Dennis tube
H. Hope, "Apparatus for growth of crystals for X-ray diffraction
study"
J. Appl. Cryst. 4 333 (1971)

Here's the kicker: Is the magnetite solution magnetic? Paramagnetic?
Makes for an interesting variable during crystallization. A tesla
permanent field is easy to obtain,

<http://www.gaussboys.com/ndfeb-magnets/75mm-circular-dipole-halbach-array.html>
elegant
http://www.unitednuclear.com/magnets.htm
"Supermagnets" Mount two in apposition.

--
Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
http://www.mazepath.com/uncleal/lajos.htm#a2
.

Relevant Pages

  • Re: Lecture of the Week: Could We Tell Life if We Saw It?
    ... Could We Tell Life If We Saw It? ... Magnetite exists in ALH84001, and Kirschvink argues that it was ... If the magnetite crystals are ... a product of Martian organisms, it is possible that the function of these ...
    (sci.bio.evolution)
  • Re: The naughty magnet
    ... Are you sure the magnetite is soluble? ... They did seem to dissolve but so slowly that it just wsn't useful. ... steam semi-reduces iron oxides and plates out magnetite inside pipes. ... "Apparatus for growth of crystals for X-ray diffraction ...
    (sci.chem)
  • Naughty magnet
    ... Magnetite, mixed-valence ferrites in general, are supremely insoluble ... in any non-reactive solvent. ... steam semi-reduces iron oxides and plates out magnetite inside pipes. ... "Apparatus for growth of crystals for X-ray diffraction ...
    (sci.physics)