Take a handful of Cobalt-Nickel (Co80-Ni20) alloy nanowires and drop them into a mixture of toluene and the synthetic polymer PMMA. Zap the mixture with a decent magnetic field, sit back and wait.
The field causes the nanowires to align and as the toluene evaporates, the PMMA traps them in place as it solidifies.
The result? A reasonably strong permanent magnet that remains magnetised at temperatures up to 250 degrees C.
Not bad eh?
Frederic “Teap” Ott at the Laboratoire Léon Brillouin in France and colleagues say the new material rivals both SmCo and AlNiCo magnets in various aspects. In particular, they reckon the new magnet is twice as good as existing materials for magnetic media recording.
Ref: arxiv.org/abs/0711.1978: Magnetic Nanowires as Permanent Magnet Materials.
Wow. AlNiCo used to be the nirvana for speaker magnets, somehow its ‘alignment’ qualities and relative efficiency led to demonstrable advantages in reproducing music. Any links to doing this on a ‘hobbyist’ basis?