Hysteresis in a magnetic bead and its applications.

We study hysteresis in a micron-sized bead: a nonmagnetic matrix embedded with superparamagnetic nanoparticles. These hold tremendous promise in therapeutic applications as heat generating machines. In this letter, we provide a theoretical framework which enables manipulation of heat dissipation by a compatible selection of commercially available beads and the frequency f and amplitude ho of the oscillating field applied in the laboratory. We also introduce a protocol for gradual heating of a local region utilizing return point memory. Easy implementation makes it potentially useful in remedial procedures such as hyperthermia and chemotherapy. [ABSTRACT FROM AUTHOR]