Nanoparticle surface charge density in ionic magnetic fluids: The effect of particle-particle interaction

In this study, particle-particle interaction in ionic magnetic fluids is systematically investigated by self-consistently solving the coupled Schrodinger and Poisson equations. It was found that particle-particle interaction changes the colloid characteristics by changing the energy level position E and the nanoparticle surface charge density sigma. Formation of bonding and antibonding states due to particle-particle interaction in a two-particle system (dimer) was studied as a function of particle diameter, particle-particle distance, and band offset. The coupling strength within the dimer is characterized by a systematic dependence of both the bonding and antibonding levels and surface charge density upon particle diameter, particle-particle distance, and band offset values. The quantum-model picture discussed in the article opens up new insights into the physics of coupled colloidal particles. (C) 2003 American Institute of Physics.