The effect of interchain coupling on energy bands and ferromagnetic order in quasi-one-dimensional organic polymer ferromagnets

Abstract

Considering the interchain interaction as an interchain electron transfer, a theoretical model is developed to describe quasi-one-dimensional organic ferromagnets. We also take into account the interaction between the itinerant electrons and the distortion of the lattice, the Hubbard electron - electron repulsion, and the antiferromagnetic correlation between the electrons and the nonbonding electrons at the site radicals. By employing the mean-field approximation, four energy bands which exhibit a three-dimensional anisotropic aspect are obtained. When the interchain coupling increases, the energy gap decreases. In the case of small dimerization order parameter, due to the interchain coupling, the band gap may disappear and the conjugated electrons in the main chain show ferromagnetic order in the ground state. The interchain coupling destabilizes the ferromagnetic ground state of the system.