Energy spectra and electric and magnetic properties of one-dimensional stacks of conjugated π-electron systems with defect surface states. II. π-systems with Schottky and chemisorption surface states

The energy spectra and magnetic properties of one-dimensional stacks consisting of polycyclic aromatic hydrocarbons with Schottky, chemisorption, and Tamm-chemisorption-type surface defects are investigated theoretically by means of the many-electron band theory. The effective spin-exchange interaction between the electrons within the half-filled bands is calculated, and the results are compared for different ordering of the radicals in the stacks. The type of defects are systematically investigated, and the obtained results show that the supermolecular stack arrangement is of primary importance for the stability of the ferromagnetic coupling of electrons within the half-filled band. Systems with ferromagnetically coupled electrons are determined, which is promising for the possible experimental preparation of pure organic materials with magnetic properties characterized with high critical temperature.