title: Brownian relaxation of interacting magnetic nanoparticles in a colloid subjected to a pulsatile magnetic field.
abstract: We have investigated and modeled the effect of interaction among magnetic particles and the magnitude and duration of external applied magnetic field on Brownian relaxation in a colloidal suspension. In the case of interacting magnetic particles, Brownian relaxation depends on the interparticle dipole-dipole interaction, which slows down the overall Brownian relaxation process of magnetic particles in the colloidal suspension. The individual magnetic particle experiences torque when a pulsatile magnetic field is applied. The torque due to the external field randomizes the particle rotation similar to that of the thermal energy. A faster Brownian relaxation is observed when individual magnetic particles are magnetized for a short duration. Magnetizing the magnetic particle for a longer duration suppress the rotational motion hence the effect of torque on Brownian relaxation.
authors.affiliation: Texas Center for Superconductivity, University of Houston, Houston, TX 77204, USA.
authors.forename: S
authors.initials: S
authors.lastname: Sarangi
authors.forename: I C
authors.initials: IC
authors.lastname: Tan
authors.forename: A
authors.initials: A
authors.lastname: Brazdeikis