STUDIES ON THE NEXT-NEAREST NEIGHBOR HOPPING INTERACTIONS OF \pi-ELECTRONS IN QUASI-ONE-DIMENSIONAL ORGANIC FERROMAGNETIC MODEL

Based on a theoretical model proposed for quasi-one-dimensional organic polymer fer-romagnets, the next-nearest neighbor hopping interactions of \pi-electrons are considered. Allowing for full lattice relaxation, a set of self-consistent equations is established to study the system. The spin-density-wave (SDW) and the possible ferromagnetic ground state of the system are investigated in detail. It is found that the next-nearest neighbor hopping in-teractions will make the SDW stronger and consequently make the ferromagnetic state more stable as compared with the nonmagnetic reference state.