Here's what you need to do:
Heat the iron just to its curie point. Cause the iron to oscillate such
that its crystal structure alternates between the two modes by
alternating just above and below the curie point. This might be
accomplished by mechanical oscillation. Alternation between pressure and
tension resulting in temperature oscillation. An ambient magnetic field
is applied to assist with the crystalization phase change. Similar to
the energy moved during phase change of liquid to gas or liquid to
freezing, there may be an energy release during phase change of the iron
from one crystal mode to the other. If the accoustical wave in the iron
mass be a standing wave, one might expect to pick up the alternating
electrical energy pumped by the phase state changes where the peaks of
the waves occur in the mass.
Of course the oscillation frequency should be at the resonant frequency
of the mass and that of iron for best efficiency. This means that the
iron mass should be dimensioned such that its accoustical resonant
frequency is harmonic with the iron resonance. Furthermore, several
elements may be combined. For example the ambient magnetic fields could
be oscillated such the the necessary pre-heating is accomplished by eddy
currents induced in the iron. The whole thing might be timed such that
the eddy currents are further pumped by the phase state change and this
is what can be tapped off as 'excess'.
Eh?
-Gerald O'