准一维有机铁磁体中的自旋耦合

The spin coupling in the quasi-one-dimensional organic ferromagnet

应用Peierls-Hubbard模型研究了一种结构类似于poly-BIPO的准一维有机铁磁体。采用Hartree-Fock近似和周期性边界条件,探讨了最近邻相互作用和次近邻相互作用对系统的铁磁基态的影响。由于最近邻与次近邻相互作用之间的竞争,导致主链上相邻格点的自旋发生反铁磁耦合→铁磁耦合的变化,形成反铁磁自旋波或铁磁自旋波作为传递媒介,使自由基自旋得以平行排列,得到高自旋的铁磁基态。

Based on the Peierls-Hubbard model, the ground state of the quasi-one-dimensional organic ferromagnets is studied by means of Hartree-Fock approximation. Due to the competition between the nearest and the next-nearest neighbor interaction, the spin coupling along the main chain will be ferromagnetic or antiferromagnetic. Mediated by the ferromagnetic spin density wave or the antiferromagnetic spin density wave along the main chain,a parallel spin arrangement of the unpaired electrons at side radical can be obtained,and the ground state of the system is ferromagnetic of highspin.