Chemical Principles of Designing Organometallic Ferromagnets

The idea of designing ferromagnets chemically boils down to uniting paramagnetic atoms by means of a chemical reaction and “turning on” positive exchange interaction between them, which aligns the atoms'electron spins into ferromagnetic order. This general idea can be tested using organometallic polymers with metal paramagnetic atoms in the polymer chain. The metal atoms are isolated by organic fragments and are not bound by exchange interaction. Two ways can be used to turn on the exchange. The first is to remove the isolating fragments between the metal atoms or to replace them by electron-conductive fragments which allow the exchange interaction. The second is to build new molecular bridges able to turn it on.