SPIN-SELECTIVE INTERACTION OF TRIPLET-EXCITED MOLECULES ON THE SURFACE OF A FERROMAGNETIC NANOPARTICLE

Influence of a magnetic field generated by a ferromagnetic nanoparticle on the annihilation of triplet-excited organic molecules or triplet excitons in a near-surface particle layer is studied. A detailed mathematical model is presented that accounts for electron excitation diffusive mobility and geometry of the system. The kinetic operator is given in the complete 9x9 basis of triplet- triplet pair spin states. Time dependencies of the singlet spin state population of the triplet-triplet pair and the dependence of the triplet-triplet annihilation magnetic response profile (magnetic reaction effect) from the magnetic field induction are obtained. It is found that the influence of a magnetic field gradient on the reaction yield dominates over the other known mechanisms of spin-dynamics in triplet- triplet pairs.