A new magnetic material: Organic ferromagnet of pyrolysed polyacrylonitrile

Abstract

Magnetic and electric properties are studied of an organic ferromagnet of pyrolysed polyacrylonitrile (PAN) and of its composites with an epoxy which are of great interest for practical use. Possible models of the pyro‐PAN ferromagnetic macromolecules are presented. Unusual magnetic properties of the composites obtained such as sign inversion of their magnetic susceptibility with increasing strength of the external magnetizing field are found. Dependences of their dielectric and magnetic constants on the electromagnetic wave frequency are obtained.

An organic approach for nanostructured multiferroics

“…Since the discovery of quasi-one-dimensional organic superconductors and conductors, low-dimensional conjugated polymer systems have attracted much interest. Several organic ferromagnets have been reported in the past with a low Curie temperature (10 K), such as poly-BIPO, [64][65][66][67] pyro-PAN 68 and macrocyclic S = 2 combined cross-linking S = 1/2 organic polymers. 69 Although many attempts have been made to synthesize new organic ferromagnets, it is still challenging to understand the origin of ferromagnetism in these polymeric materials.…”

Magnetism of Carbon‐Based Materials

“…. Magnetic and electrical properties of pyrolized polyacrylonitrile (pyro-PAN) has been studied, and possible models of ferromagnetism in this organic substance are presented [58]. A technical PAN (-CH 2 -CH -CN -) n is a diamagnetic compound, while the product of its pyrolysis is a ferromagnet, slowly degrading with time being exposed to air.…”

Spin-charge disparity of polarons in organic ferromagnets

“…Organic ferromagnets are particularly fascinating since they combine ferromagnetic and polaronic properties. Purely organic ferromagnets not containing transitionmetal ions can be realized by using spin radicals [8][9][10][11][12], which are usually heterocycles containing an unpaired electron [13]. For example, the organic ferromagnet poly-BIPO can be obtained from polyacetylene by replacing every other H atom by a spin radical [8,9].…”