Double ferromagnetism

This allows one to propose that it has three magnetic phases, double ferromagnetism below Tc = 217K, a helical antiferromagnetic state n = 205 K and a ferromagnetic state below 200 K. 

Finally, synthetic metals made of polymeric organic molecules may also show the property of ferromagnetism. Organic materials of this kind were first demonstrated in 1987 by Ovchinnikov and his co-workers at the Institute of Chemical Physics in Moscow. The polymer they used was based on a polydiacetylene backbone, which contains alternating double-single and triple-single bonds between the carbon atoms of the molecule (10.2). 

Dy3+-Dy3+ ferromagnetic coupling has also been observed in a double chain based on the triangular motif (topologic mode (B) in Scheme 4.1) [74]. Slow relaxation is observed (A = 44.2K, r0 = 2.4 X 10-8 s) but its ID origin is not demonstrated, and the onset of 3D ordering is visible at low temperature. 

The fact that LSMO is ferromagnetic in the charge-ordered, insulating state is remarkable, since it indicates that the ferromagnetic interaction at low temperatures cannot arise from the double exchange mechanism. We note here that other... 

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